Answer:
#showerthoughts
Explanation:
An athlete at the gym holds a 3.0 kg steel ball in his hand. His arm is 60 cm long and has a mass of 3.8 kg, with the center of mass at 40% of the arm length from the shoulder.
a. What is the magnitude of the torque about his shoulder due to the weight of the ball and his arm if he holds his arm straight out to his side, parallel to the floor?
b. What is the magnitude of the torque about his shoulder due to the weight of the ball and his arm if he holds his arm straight, but 45∘ below horizontal?
Answer:
(a) τ = 26.58 Nm
(b) τ = 18.79 Nm
Explanation:
(a)
First we find the torque due to the ball in hand:
τ₁ = F₁d₁
where,
τ₁ = Torque due to ball in hand = ?
F₁ = Force due to ball in hand = m₁g = (3 kg)(9.8 m/s²) = 29.4 N
d₁ = perpendicular distance between ball and shoulder = 60 cm = 0.6 m
τ₁ = (29.4 N)(0.6 m)
τ₁ = 17.64 Nm
Now, we calculate the torque due to the his arm:
τ₁ = F₁d₁
where,
τ₂ = Torque due to arm = ?
F₂ = Force due to arm = m₂g = (3.8 kg)(9.8 m/s²) = 37.24 N
d₂ = perpendicular distance between center of mass and shoulder = 40% of 60 cm = (0.4)(60 cm) = 24 cm = 0.24 m
τ₂ = (37.24 N)(0.24 m)
τ₂ = 8.94 Nm
Since, both torques have same direction. Therefore, total torque will be:
τ = τ₁ + τ₂
τ = 17.64 Nm + 8.94 Nm
τ = 26.58 Nm
(b)
Now, the arm is at 45° below horizontal line.
First we find the torque due to the ball in hand:
τ₁ = F₁d₁
where,
τ₁ = Torque due to ball in hand = ?
F₁ = Force due to ball in hand = m₁g = (3 kg)(9.8 m/s²) = 29.4 N
42.42 cm = 0.4242 m
τ₁ = (29.4 N)(0.4242 m)
τ₁ = 12.47 Nm
Now, we calculate the torque due to the his arm:
τ₁ = F₁d₁
where,
τ₂ = Torque due to arm = ?
F₂ = Force due to arm = m₂g = (3.8 kg)(9.8 m/s²) = 37.24 N
d₂ = perpendicular distance between center of mass and shoulder = 40% of (60 cm)(Cos 45°) = (0.4)(42.42 cm) = 16.96 cm = 0.1696 m
τ₂ = (37.24 N)(0.1696 m)
τ₂ = 6.32 Nm
Since, both torques have same direction. Therefore, total torque will be:
τ = τ₁ + τ₂
τ = 12.47 Nm + 6.32 Nm
τ = 18.79 Nm
A)The magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor will be 26.58 Nm.
What is torque?Torque is the force's twisting action about the axis of rotation. Torque is the term used to describe the instant of force. It is the rotational equivalent of force. Torque is a force that acts in a turn or twist.
The amount of torque is equal to force multiplied by the perpendicular distance between the point of application of force and the axis of rotation.
m is the mass of steel ball = 3.0 kg in his hand.
L is the length of the arm is 60 cm long
M is the mass of arm=3.8 kg,
The torque is given as;
The magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor is found as;
[tex]\rm \tau_1 = F \times d \\\\ \rm \tau_1 = 29.4 \times 0.63 \\\\ \rm \tau_1 =17.64 \ Nm[/tex]
The torque due to the arm;
[tex]\rm \tau_2= F \times d \\\\ \rm \tau_2 = mg \times d \\\\ \rm \tau_2 =3.8 \times 9.81 \times 0.24 \ Nm \\\\ \rm \tau_2=8.94 \ Nm[/tex]
The net torque for case 1 will be;
[tex]\tau = \tau_1 + \tau_2\\\\ \rm \tau = 17.64 Nm + 8.94 Nm\\\\ \tau = 26.58 Nm[/tex]
Hence the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor will be 26.58 Nm.
B) the magnitude of the torque about his shoulder if he holds his arm straight, but 45∘ below horizontal will be 18.79 Nm.
The torque is due to the weight of the ball;
[tex]\rm \tau_1= F \times d \\\\ \rm \tau_1 = mg \times d \\\\ \rm \tau_1 =3.8 \times 9.81 \times 0.4242 \ Nm \\\\ \rm \tau_1= 12.47 \ Nm[/tex]
The torque due to the arm will be;
[tex]\rm \tau_2= F \times d \\\\ \rm \tau_2 = mg \times d \\\\ \rm \tau_2 =3.8 \times 9.81 \times 0.1696 \ Nm \\\\ \rm \tau_2=6.32 \ Nm[/tex]
The net torque in case 2 will be
[tex]\tau = \tau_1 + \tau_2\\\\ \rm \tau = 12.47 Nm + 6.32 Nm\\\\ \tau = 18.79 Nm[/tex]
Hence the magnitude of the torque about his shoulder if he holds his arm straight, but 45° below horizontal will be 18.79 Nm
To learn more about the torque refer to the link;
brainly.com/question/6855614
In Figure 4.27 four particles form a square of edge length
a=5cm and have charges q1=+10nc, q2=-20nc,q3 = +20nc, q4=-10.0nc. In unit-rector notation, what net
electric field do the particles produce at the centre of square?
Answer:
so sorry
don't know but please mark me as brainliest please
A 6.00 kg box is resting on a table. What is the magnitude of the normal force of the table on the box?
Answer:
to get it u have to multiple 6=00 time 89 to get the number 21 than plus it by 22 what is 31
Chris and Jamie are carrying Wayne on a horizontal stretcher. The uniform stretcher is 2.00 m long and weighs 100 N. Wayne weighs 800 N. Wayne's center of gravity is 75.0 cm from Chris. Chris and Jamie are at the ends of the stretcher. The force that Chris is exerting to support the stretcher, with Wayne on it, is:_________.a. 250 N. b. 350 N. c. 400 N. d. 550 N. e. 650 N.
Answer:
E. 650NExplanation:
step one:
given
length of stretcher= 2m
weight of stretcher=100N
Wayne weighs =800N
distance of Wayne weighs from chris's end= 75cm= 0.75m
The force that Chris is exerting to support the stretcher, with Wayne on it, can be computed by taking moments of the weight of the stretcher and Wayne weighs about Chris's end, the end result is the reaction at Chris's end
Taking moment about Chris's end
The moment of Wayne weight 75cm from Chris+ Half the weight of stretcher 1m from Chris
0.75*800+50*1=0
600+50=0
650N
hello, I need help with a question
what force noncontact force:
a. buoyancy
b. friction
c. air reistanceses
d. Gravity
(please if youre not sure whats the answer dont answer it
Answer:
The Answer is (A) . . .
I Think . . .
Answer:
a. buoyancy
....................
Explain how you would determine how much error there is between a vector addition and the displacement of the actual trip taken. Why aren’t vectors true straight - line paths in the real world? Would you expect the vector addition to be larger or smaller than the actual trip taken? Why?
Answer:
find the difference"vector addition" is likely to be larger than displacementExplanation:
No doubt your curriculum materials have an adequate discussion of error and how it is determined.
a) The error between two values is the difference between an approximation and the true value. You determine it by subtracting the true value from the approximation.
In the case of a trip, you need to decide what is the "true value" and what is the "approximation." The wording here suggests that the "displacement of the actual trip taken" is to be considered the "true value." Then, you determine the error by subtracting that displacement from the "vector addition."
__
b) In Euclidean geometry, a vector is a straight-line path. In the real world, we use the term vector to refer to the direction taken by an object, generally along a curved path at some relative distance from the Earth's surface. The direction reference may change along the path, so that following a given "vector" will usually result in a curved path (not a great circle) on the Earth's surface.
__
c) The curved path from a point A to a point B on the Earth's surface will always be longer than the straight-line path between the same two points. In the case of points on opposite sides of the world, the straight-line path is through the center of the Earth, whereas the "vector addition" will be some path along the surface of the Earth.
You need to decide the meaning of "actual trip taken," as any actual trip will generally involve all the changes in direction and ups and downs along the way. If you consider "the actual trip taken" to be the difference between starting and ending coordinates, then the "vector addition" will always be longer.
An element with 5 protons, 6 neutrons, and 8 electrons has an atomic number of
(2 Points)
Answer:
I've attached a screenshot of a document from K12 that should give you the answer to your question, and many more question you might have. If this is not helpful please say so in the replies to this answer and I'll try my best to find some more information.
Explanation:
May I have brainliest please? :)
Begin any simulation, and turn on Gravity Force in the central menu on the right. The gravity force arrow shows the direction and strength of the gravitational force each body feels. How do the gravity force arrows change throughout the orbit?
Answer:
The gravity arrow for each body rotates, always pointing toward the other body. Both arrows grow longer when the bodies come closer to one another and shorter when they move farther apart. This change shows that the gravitational force is stronger the closer together the bodies are.
Explanation:
A gravitational field is a model used in physics to explain the effects that a large thing has on the area surrounding it, exerting a force on smaller, less massive bodies. Thus, a gravitational field—measured in newtons per kilogram (N/kg)—is employed to describe gravitational processes.
What strength of the gravitational force each body feels?Each body's gravity arrow spins while constantly pointing in the direction of the other body. When the bodies move apart, the arrows go shorter and get longer as they get closer together. This modification demonstrates that the gravitational force increases with increasing body proximity.
Therefore, All objects with mass are attracted to one another by the gravitational attraction. Which has a magnitude that is directly proportional to the masses of the two objects and inversely proportional to the square of their distance from one another.
Learn more about gravitational force here:
https://brainly.com/question/12528243
#SPJ2
A 0.0138-m3 container is initially evacuated. Then, 4.73 g of water is placed in the container, and, after some time, all of the water evaporates. If the temperature of the water vapor is 358 K, what is its pressure?
Answer:
56.7kpa
Explanation:
V = 0.0138-m³
M = 4.73g
T = 358k
R = ideal gas constant = 8.314
Number of moles of water n = 4.73/18 = 0.2628 (Remember that the molecular mass of water is 18).
Pv = nRT
P = nRT/V
P = (0.2628x8.314x358)/0.0138
P = 56681.23
P = 56.7Kpa
56.7Kpa is therefore the pressure of the water vapor.
Which two components must a vector quantity
have?
a. Magnitude and velocity
b. Acceleration and direction
c. Force and speed
d. Direction and magnitude
Answer:
d. Direction and magnitude
Explanation:
The two components of a vector are its magnitude and direction.
Magnitude is the quantity of the substance
Direction is the path.
Other quantities are called scalar quantities. Scalar quantities have only magnitude but no direction.Examples of vector quantities are velocity, displacement, acceleration.
When you drop a pebble into a pond, the energy from the pebble acts on the water and causes waves. What is the wave?
Group of answer choices
The water moving away
The pebble falling through the water
The visible form of energy.
Answer:
The visible form of energy
Explanation:
Watch a video on it, and took test and got it right :)
Answer:
The visible form of energy
Explanation:
An unknown charged particle passes without deflection through crossed electric and magnetic fields of strengths 187,500 V/m and 0.1250 T respectively. The particle passes out the electric field but the magnetic field continues, and the particle makes a semicircle of diameter 25.05 cm. Part A. What is the particles charge to mass ratio?Part B. Can you identify the particle?
a. can't identify
b. proton
c. electron
d. neutron
Answer:
(A) q/m = 9.58 x 10⁷ C/kg
(B) b. Proton
Explanation:
(A)
In order to pass un-deflected between magnetic and electric field both electric and magnetic forces must be equal:
Felectric = Fmagnetic
Eq = Bqv
v = E/B ------------ equation (1)
Now, when the particle forms semi-circle under influence of magnetic field. At this, point magnetic field is equal to centripetal force:
Centripetal Force = Magnetic Force
mv²/r = qvB
mv = qrB
v = qrB/m ------------ equation (2)
comparing equation (1) and equation (2), we get:
E/B = qrB/m
q/m = E/B²r
where,
q/m = charge to mass ratio = ?
E = Electric Field = 187500 V/m
B = Magnetic Field = 0.125 T
r = radius of circular path = 25.05 cm/2 = 12.525 cm = 0.12525 m
Therefore,
q/m = (187500 V/m)/(0.125 T)²(0.12525 m)
q/m = 9.58 x 10⁷ C/kg
(B)
This is the charge to mass ration of a proton:
q/m = 1.6 x 10⁻¹⁹ C/1.67 x 10⁻²⁷ kg
q/m = 9.58 x 10⁷ C/kg
Therefore, correct option is:
b. proton
Which TWO statements describe the ocean floor giving brainliest please help
Answer:
A and B.
Explanation:
Answer C is wrong - there are no tall trees underwater
Answer D is wrong, there are mountain chains underwater due to plate tectonics.
What is the p.d. across a 4 resistor when there is a current of 0.3 A in it?
Answer:
1.2V
Explanation:
Given parameters:
Resistance = 4Ω
Current = 0.3A
Unknown:
Potential difference = ?
Solution:
To find the potential difference, we use the ohms law;
V = IR
Now, insert the parameters and solve;
V = 0.3 x 4 = 1.2V
What is a concern about recovered memories?
A. Some recovered memories reveal child abuse.
B. Some recovered memories are false.
C. Recovered memories help people grow emotionally stronger.
D .choices A and B
Answer:
D because those are both concerning.
What is a safe following distance between your automobile and the vehicle in front of you?
Answer:
Many drivers follow the “three-second rule.” In other words, you should keep three seconds worth of space between your car and the car in front of you in order to maintain a safe following distance.
Thank you and please rate me as brainliest as it will help me to level up
a race car with a mass of 500 kg on a bridge 45 m above a river what is the potential energy of the car?
The electric field a distance of 10 km from a storm cloud is 1,000 N/C . What is the approximate charge in the cloud?a. 0.0011 Cb. 11 Cc. 110 Cd. 1,100 C
Answer:
The approximate charge in the cloud is 11 C
(b) 11 C
Explanation:
Given;
electric field strength, E = 1,000 N/C
separation distance, r = 10 km, = 10,000 m
Electric field strength is given by the following equations;
[tex]E = \frac{F}{q} = \frac{kq^2}{r^2}*\frac{1}{q} = \frac{kq}{r^2} \\\\q = \frac{Er^2}{k}[/tex]
where;
k is coulomb's constant = 8.99 x 10⁹ Nm²/C²
[tex]q = \frac{Er^2}{k} \\\\q = \frac{(1000)(10000)^2}{(8.99*10^9)} \\\\q = 11.12 \ C[/tex]
q ≅ 11 C
Therefore, the approximate charge in the cloud is 11 C.
Correct option is "B"
A bottle salad dressing must be shaken before it is poured onto a salad in order to evenly mix the particles . How can this salad dressing be classified
A.colloid
B.solution
C.suspension
D.compound
Answer:
D. compound. Google says salad dressing is a compound. Sorry if it's wrong.
Explanation:
What is the lift (in newtons) due to Bernoulli's principle on a wing of area 87 m2 if the air passes over the top and bottom surfaces at speeds of 260 m/s and 170 m/s respectively?
Answer:
Explanation:
According to Bernoulli's principle
P₁ + 1/2ρ v₁² + ρgh₁ = P₂ + 1/2ρ v₂² + ρgh₂ , ρ is density of air . P₁ , P₂ are pressures at two surfaces .
h₁ = h₂
P₁ - P₂ = 1/2ρ( v₂² - v₁² ) = Lift pressure
ρ of air = 1.225 kg / m³
P₁ - P₂ = 1/2ρ( v₂² - v₁² )
= .5 x 1.225 ( 260² - 170² )
= .5 x 1.225 ( 67600- 28900 )
= 23703.75 N/m²
Lift Force = pressure x area
= 23703.75 x 87
= 2062226.25 N .
The upper arm muscle is _______________ to the skin.
Answer:
The pectoralis major, latissimus dorsi, deltoid, and rotator cuff muscles connect to the humerus and move the arm. The muscles that move the forearm are located along the humerus, which include the triceps brachii, biceps brachii, brachialis, and brachioradialis.
-Two pickup trucks each have a mass of 2,000 kg. The gravitational force between the
trucks is 3.00 x 10-5 N. One pickup truck is then loaded with 1,000 kg of bricks. Which
of the following would be the new gravitational force between the two trucks?
Answer:
[tex]F'=4.5\times 10^{-5}\ N[/tex]
Explanation:
The gravitational force between two pickups is given by :
[tex]F=G\dfrac{m_1m_2}{r^2}[/tex]
It means,
[tex]F\propto m_1m_2[/tex]
So,
[tex]\dfrac{F}{F'}=\dfrac{m_1m_2}{m_1'm_2'}[/tex]
We have,
[tex]m_1=m_2=2000\ kg\\\\F=3\times 10^{-5}\ N\\\\m_1'=2000+1000 =3000\ kg\\\\m_2'\ \text{remains the same i.e. 1000 kg}[/tex]
F' is the new force
So, putting all the values,
[tex]\dfrac{3\times 10^{-5}}{F'}=\dfrac{2000\times 2000}{3000\times 2000}\\\\\dfrac{3\times 10^{-5}}{F'}=\dfrac{2}{3}\\\\F'=\dfrac{9\times 10^{-5}}{2}\\\\F'=4.5\times 10^{-5}\ N[/tex]
So, the new force between the two trucks is [tex]4.5\times 10^{-5}\ N[/tex].
Please help me out as soon as you can really need help. You can move the picture and see the whole problem.
ANSWER : 20 is the answer
Explanation:
If you take 40, then divide it by 2, you get 20. That is how you do the problem.
Can you please mark brainless? It couldn't hurt? STAY SAFE ! :)
Which of the following is an example of a force that acts at a distance? *
a bear walking through the woods
a jet ski skimming across the water
a leaf falling off of a tree to the ground
a tennis ball hit by a tennis player's racket
lucia raced her car on a raceway
Answer:
Good question to ask in physics, sir maam
Answer:
That's good
Explanation:
A car turns from a road into a parking lot and into an available parking space. The car’s initial velocity is 4 m/s [E 45° N]. The car’s velocity just before the driver decreases speed is 4 m/s [E 10° N]. The turn takes 3s. What's the average acceleration of the car during the turn? The answer should have directions with an angle.
Write the velocity vectors in component form.
• initial velocity:
v₁ = 4 m/s at 45º N of E
v₁ = (4 m/s) (cos(45º) i + sin(45º) j)
v₁ ≈ (2.83 m/s) i + (2.83 m/s) j
• final velocity:
v₂ = 4 m/s at 10º N of E
v₂ = (4 m/s) (cos(10º) i + sin(10º) j)
v₂ ≈ (3.94 m/s) i + (0.695 m/s) j
The average acceleration over this 3-second interval is then
a = (v₂ - v₁) / (3 s)
a ≈ (0.370 m/s²) + (-0.711 m/s²)
with magnitude
||a|| = √[(0.370 m/s²)² + (-0.711 m/s²)²] ≈ 0.802 m/s²
and direction θ such that
tan(θ) = (-0.711 m/s²) / (0.370 m/s²) ≈ -1.92
→ θ ≈ -62.5º
which corresponds to an angle of about 62.5º S of E, or 27.5º E of S. To use the notation in the question, you could say it's E 62.5º S or S 27.5º E.
Suppose a boat is moving 6m/s relative to the pier, but you are walking on the boat -1 m/s relative to the boat' What would be your relative velocity to the pier? What direction would the boat be moving? Is this a one or two-dimensional problem?
Answer:
V₁ = 5 m/s
This is the problem of one dimension
Explanation:
Before using the concepts of relative velocity, we must first define the variables for each velocity here:
V₁ = Person's Velocity Relative to Pier = ?
V₂ = Boat's Velocity Relative to Pier = 6 m/s
V₁₂ = Person's Velocity Relative to Boat = - 1 m/s
Now, from the relative velocity, we know that:
V₁₂ = V₁ - V₂
- 1 m/s = V₁ - 6 m/s
V₁ = 6 m/s - 1 m/s
V₁ = 5 m/s
This is the problem of one dimension
because, the velocity is along single dimension with opposite directions. No, second dimension is involved.
If an object moves in a circle at a constant speed, its velocity vector will be constant. true or false
Answer:
False
Explanation:
For the vector to remain the same, the magnitude and the direction of the object must be constant. But when an object is travelling in a circular motion, it keeps on accelerating due to the change in direction, even if its motion is uniform. Quite clearly its velicity won't be constant although, its speed might be.
Which of the following is a characteristic of active galaxies? A. They generally exhibit no signs of explosive activity. B. Their energy emission cannot be explained as the accumulated emission of their stars. C. They are generally less luminous than normal galaxies. D. Their energy output is steady in time.
Answer:
The correct option is B
Explanation:
Active galaxies are characterized by a small core of emission at the center which is usually brighter than the rest of the galaxy. The energy emitted from active galaxy is way more than that emitted from normal galaxy. As compared to normal galaxy where it's energy emission is thought to be the sum of the emission from each star found in the galaxy, this is not true or the same in active galaxy. There (active galaxy) huge energy emission cannot be explained as the sum of the emission of their stars.
A 52.0-kg sandbag falls off a rooftop that is 22.0 m above the ground. The collision between the sandbag and the ground lasts for a total of 17.0 ms. What is the magnitude of the average force exerted on the sandbag by the ground during the collision?
Answer:
F = 7,916,955.0N
Explanation:
According to newtons second law
Force = mass * acceleration
Given
mass = 52.0kg
distance S = 22.0m
time t = 17.0 ms = 0.017s
We need to get the acceleration first using the formula;
S = ut+ 1/2at²
22 = 0 + 1/2 a(0.017²)
22 = 0.0001445a
a = 22/0.0001445
a = 152,249.13m/s²
The magnitude of the average force exerted will be;
F = ma
F = 52 * 152,249.13
F = 7,916,955.0N
