Answer:
Why do you do sports, when you could be a doctor and helping the sick children, or saving the worlds ocean?
Explanation:
In a block-spring system
m = 0.25kg
and
k = 4N /m
. At
t = 0.15s
, the velocity is
v = −0.174m/s
and
the acceleration
2
a = +0.877m /s
. Write an expression for the displacement as a function of time,
x(t)
Answer:
the answer is b
Explanation:
An expression for the displacement as a function of time is x(t) = a sin wt.
What is Displacement?Displacement is defined as the change in position of an object. It is a vector quantity and has a direction and magnitude. The spacing between two specified points is represented by displacement, a one-dimensional measure commonly known as length or distance.
Given in the question we have to find the displacement of the as function of time
The equation used of express displacement is.
d = V i t + 1 2 a t 2
Displacement = Final position – initial position = change in position.
so, x = A sin wt is equation where A is amplitude and t is time period.
An expression for the displacement as a function of time is x(t) = a sin wt.
Thus, an expression for the displacement as a function of time is x(t) = a sin wt.
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the change in resistance of a metallic conductor at temperature below 0°C is
A. Linear
B. Non linear
C. Curve
D. Curvilinear
Answer:
A: Linear
Explanation:
Formula for Resistance of a metallic conductor is given as;
R = R_o(1 + αΔT)
Where;
R_o is the original resistance
R is the final resistance after change in temperature
ΔT is change in temperature
α is coefficient of linear expansion
Now, from the formula given, we can see that the change in resistance is directly proportional to the change in temperature.
Thus, the higher the final temperature, the more the change in resistance and the lower the final temperature, the lesser the change in resistance.
Thus, for temperature less than zero, since the change is resistance is directly proportional to the temperature, it means it follows a linear relationship.
An 11-kilogram cart is pulled with a horizontal force at a constant velocity of 8.0 meters per second, as shown in the diagram. The force of friction between the cart and the floor is 12 newtons. What is the magnitude of the horizontal force?
The cart is pulled at a constant velocity, so it is in equilibrium. In particular, the net horizontal force is zero, and consists of only the pulling force and friction such that
p - f = 0
where p and f denote the magnitudes of the pulling force and friction.
So we have
p - 12 N = 0
p = 12 N
A wooden block contains some nails so that its density is exactly equal to that of water. If it is placed in a tank of water and released from rest when it is completely submerged, it will:_____.a. remain where it is released. b. rise to the surface. c. sink to the bottom.
Answer:
The correct answer is:
a) remain where it is released
Explanation:
The concept of density seeks to measure the weight of an object in relation to its size. It is the measure of how packed together the particles of that object are. An object placed in a liquid displaces a certain volume of the liquid, based on the relative density of the object and the liquid.
If an object is less dense than a liquid in which it is placed, it displaces a smaller volume of the liquid than its volume, hence only some part of the object will be seen to be under the liquid, the other part will float.
If an object is denser than the liquid in which it is placed, it displaces a larger volume of the liquid than its own volume, making the object to sink and is submerged, sometimes to the bottom of the liquid, but mostly below the point at which it was released.
Finally, if the density of an object and the liquid into which it is submerged is the same. the object's mass per unit volume is the same as the liquid's mass per unit volume, hence the weight and force created due to density will balance and cancel each other out hence making the object to remain where it was submerged.
To overcome an object's inertia, it must be acted upon by __________. A. gravity B. energy C. force D. acceleration
Sully is riding a snowmobile on a flat, snow-covered surface with a constant velocity of 10 meters/second. The total mass of the snowmobile, including Sully, is 280 kilograms. If Sully accelerates to a velocity of 16 meters/second over 10 seconds, what’s the force exerted by the snowmobile to accelerate? Use F = ma, where . A. 160 N B. 168 N C. 248 N D. 280 N E. 324 N
Answer:
280.6N
Explanation:
According to Newton's second law;
Force = mass * acceleration
Given
Mass = 280kg
velocity = 10m/s
Time = 10 secs
Acceleration = velocity?/Time
Force = mass * velocity/time
Force = 280 + (16-10/10)
Force = 280 + 0.6
Force = 280.6N
Hence the force exerted by the snowmobile to accelerate is 280.6N
Answer:168 N
Explanation:
PLEASE IM TIMED
If total mechanical energy = kinetic energy + potential energy, TME = KE + PE, and a roller coaster has 500 J of total mechanical energy. At the very beginning of the track the roller coaster has 500 J of potential energy, how much kinetic energy is there at the beginning of the track?
Answer:
As already mentioned, the mechanical energy of an object can be the result of its motion (i.e., kinetic energy) and/or the result of its stored energy of position (i.e., potential energy). The total amount of mechanical energy is merely the sum of the potential energy and the kinetic energy.
Explanation:
Is a light bulb that is off potential energy or kinetic energy?
A projectile is launched straight upward at 50 m/s. Neglecting air resistance its speed upon returning to its starting point is:________.
Answer:
The speed of the projectile upon returning to its starting point is 50 m/s.
Explanation:
Given;
initial velocity of the projectile, u = 50 m/s
The velocity of the projectile is maximum before hitting the ground. As the object moves upward, the velocity reduces as it approaches the maximum height, at the maximum height the velocity becomes zero. Also, as the object moves downward, the velocity starts to increase and becomes maximum before hitting the ground.
Therefore, the speed of the projectile upon returning to its starting point is 50 m/s.
A car is initially moving at 100 m/s and decides to gun it. They accelerate at a rate of 20 m/s/s for 10 seconds. How far did they travel during this time period?
Answer:
dx = 2000 [m]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]dx =v_{o}*t +\frac{1}{2} *a*t^{2}[/tex]
where:
dx = distance [m]
Vo = initial velocity = 100 [m/s]
a = acceleration = 20 [m/s²]
t = time = 10 [s]
dx = 100*10 + 0.5*20*10²
dx = 2000 [m]
Note: the positive sign in the above equation means that the car is increasing its velocity.
Much of the energy of falling water in a waterfall is converted into heat. If all the mechanical energy is converted into heat that stays in the water, how much of a rise in temperature occurs in a 111 m waterfall?
Answer:
Explanation:
potential energy of water is converted into heat energy
P E = mgh = m x 9.8 x 111
= 1087.8 m .
Let rise in temperature θ
m x s x θ = heat absorbed
m x s x θ = 1087.8 m
m x 4182 x θ = 1087.8 m
θ = 0.26 degree celsius .
Unpolarized light passes through two Polaroid sheets. The transmission axis of the second polarizing filter makes an angle of 340 with the axis of the first polarizer. What fraction of the original unpolarized light is transmitted through the second polarizing filter?
This question is incomplete, the complete question is;
Unpolarized light passes through two Polaroid sheets. The transmission axis of the second polarizing filter makes an angle of 34° with the axis of the first polarizer. What fraction of the original unpolarized light is transmitted through the second polarizing filter?
Answer: the fraction of the original unpolarized light transmitted through the second polarizing filter is 0.343
Explanation:
We know that when Unpolarized light passes through first polarizer, it's intensity will be reduced to half i.e
I1 = I0/2
Now after that when light passes through 2nd polarizer, Intensity will be;
I2 = I1 × (cos A1)²
but I1 = I0/2
so
I2 = (I0/2) × (cos A1)²
I2/I0 = 0.5 × (cos A1)²
In the question we were given that; The transmission axis of the second polarizing filter makes an angle of 34° with the axis of the first polarizer
so A = 34°
so we substitute
I2/I0 = 0.5 × (cos 34)²
I2/I0 = 0.343
Therefore the fraction of the original unpolarized light transmitted through the second polarizing filter is 0.343
Kate is creating two models to describe the effect of thermal energy on the movement of particles in a liquid. She draws the first model of a liquid sample. Her model is shown below.
Explanation:
so sorry
don't know but please mark me as brainliest please
How much work is done when you push a table with 300 N of force 5 m across a room?
What are some tasks that organelles perform inside of a cell?
Answer:
Different organelles play different roles in the cell — for instance, mitochondria generate energy from food molecules; lysosomes break down and recycle organelles and macromolecules; and the endoplasmic reticulum helps build membranes and transport proteins throughout the cell.
Explanation:
Hopefully this helped!
given a circuit powered at 12V with R1, R2, R3 respectively of 10,20,30 Ohm, determine R4 in such a way that the Wheatstone bridge is in equilibrium and then calculate voltages and currents as for reference exercise.
Answer:
The balanced condition for Wheatstones bridge is
Q
P
=
S
R
as is obvious from the given values.
No, current flows through galvanometer is zero.
Now, P and R are in series, so
Resistance,R
1
=P+R
=10+15=25Ω
Similarly, Q and S are in series, so
Resistance R
2
=R+S
=20+30=50Ω
Net resistance of the network as R
1
and R
2
are in parallel
i=
R
V
=
50
6×3
=0.36 A.
Explanation:
Dos niños sostienen una piñata cuyo peso es de 196N, formando un ángulode 140°con ambas cuerdas. Calcular la fuerza aplicada por cada niño
Answer:
T = 104.2 N
Explanation:
For this exercise we must define a coordinate system, the x axis is horizontal and the y axis is vertical, let's write the equilibrium equations on each axis
X axis
T₁ₓ-T₂ₓ = 0
T₁ₓ = T₂ₓ (1)
y axis
[tex]T_{1y}[/tex] + T_{2y} - W = 0
T_{1y} + T_{21y} = W (2)
Let's use trigonometry to find the decomposition of the stresses, they indicate that the angle between the two forces is 140º, but each force has an angle of 70º
cos 70 = T₁ₓ / T₁
T₁ₓ = T₁ cos 70
sin 70 = [tex]T_{1y}[/tex] / T₁
T_{1y} = T₁ sin 70
for tension 2 we have a similar equation
T₂ₓ = T₂ cos 70
T_{2y} = T₂ sin 70
From equation 1
T₁ cos 70 = T₂ cos 70
T₁ = T₂
therefore the two children apply the same force
From equation 2
T sin 70 + T sin 70 = W
2 T sin 70 = W
T = W / 2sin 70
T = 196 / (2 sin 70)
T = 104.2 N
the two children have the same strength
Explain how you would make a cast of a shoeprint in left in the mud
Answer:
Put some melted plastic over the print and let it harden
Explanation:
I think that's how the police do it
An object of mass 3.4 kg is moving in a straight line with kinetic energy 59.177 J. A force is applied in the direction of its motion for 2.7 seconds, and as a result, its kinetic energy is multiplied by a factor of 1.57. By what factor is its momentum multiplied?
Answer:
Its momentum is multiplied by a factor of 1.25
Explanation:
First, we calculate the initial velocity of the object:
K = 0.5 * m * v₁²59.177 J = 0.5 * 3.4 kg * v₁²v₁ = 5.9 m/sWith that velocity we can calculate the initial momentum of the object:
p₁ = v₁ * mp₁ = 20.06 kg·m/sThen we calculate the velocity of the object once its kinetic energy has increased:
(59.177 J) * 1.57 = 0.5 * 3.4 kg * v₂²v₂ = 7.4 m/sAnd calculate the second momentum of the object:
p₂ = v₂ * mp₂ = 25.16 kg·m/sFinally we calculate the factor:
p₂/p₁ = 1.25A student travels 200 m north and then 500 m east to get to school. What is the shortest distance that he could travel between home and school?
A.700
B.300
C.539
D.458
Answer:
B???
Explanation:
guess
The shortest distance that the student could travel between home and school is approximately 539 meters.
Hence Option C) 539m is the correct answer.
Given the data in the question;
As illustrated in the image below,
Distance traveled by student towards north; [tex]b = 200m[/tex]Distance traveled by student towards east; [tex]a = 500m[/tex]We get a right angled triangle and the hypotonus "c" is the shortest distance from the student's house to her school.
Now, using Pythagorean theorem:
[tex]a^2 + b^2 = c2[/tex]
We substitute our values into the expression and solve for "c"
[tex](500m)^2 + (200m)^2 = c^2\\\\250000m^2 + 40000m^2 = c^2\\\\c^2 = 290000m^2\\\\c = \sqrt{290000m^2}\\\\c = 539 m[/tex]
The shortest distance that the student could travel between home and school is approximately 539 meters.
Hence Option C) 539m is the correct answer.
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Net force causes motion.
Answer: If you want me to write them for you here they are
Explanation:
Net force causes change in motion because a net external force causes a change in motion; thus, we see that a net external force causes acceleration.
Not more likely to be Net force motion because if it doesnt say change then its gonna stay the same so Net force does cause change in a motion because take for example if you are going to bounce a basketball its gonna change its position from one place to another thats how Net force causes Change in motion.
Hope this helps :)
Select the correct answer from each drop-down Box menu Debbie places to shopping carts in a car corral she pushes the first car which then pushes a second car what force is being exerted Debbie exerts blank force on the first shopping cart the first card exerts blank force on the second card
Answer: Debbie exerts applied force on the first cart.
Explanation:
The first cart exert applied force on the second cart.
A radioactive atom has just undergone nuclear decay. Its mass number is now four less than the original atom. Which type of nuclear decay has occurred?
Answer:
Explanation:
mass number is now 4 times less than the original value so alpha decay occur during alpha decay the mass number is decreased 4 times and atomic number decreased 2 times than the original value
A golfer attempts a birdie putt, sending the 0.050-kg ball toward the hole with a speed of 1.4 m/s. Unfortunately, the ball does a "horseshoe" and goes halfway around the rim of the hole. The ball ends up heading back toward the golfer with a speed of 1.3 m/s.If we take the positive direction to be from the golfer to the hole, what is the impulse delivered to the ball by the hole?
Answer:
I = - 0.135 kg m/s
Explanation:
The formula to calculate the impulse of delivered to the ball is:
I = Ft
where,
I = Impulse delivered to the ball by hole = ?
F = Force = ma (By Newton's Second Law)
t = time
Therefore,
I = mat
where,
m = mass of ball = 0.05 kg
a = acceleration of ball = (Vf - Vi)/t
Therefore,
I = m[(Vf - Vi)/t]t
I = m(Vf - Vi)
where,
Vf = Final velocity = - 1.3 m/s
Vi = Initial Velocity = 1.4 m/s
Therefore,
I = (0.05 kg)(- 1.3 m/s - 1.4 m/s)
I = - 0.135 kg m/s
The pupil of a cat's eye narrows to a slit width of 0.5 mm in daylight. What is the angular resolution of the cat's eye in daylight (wavelength = 500 nm)?
A. 0.01 rads
B. 10-5 rads
C. 10-3 rads
D. 10-4 rads
Answer:
C. 10⁻³ rads
Explanation:
Here, we shall use Rayleigh's Criterion to find out the angular resolution of Cat's eye during day light. Rayleigh's Criterion is written as follows:
θ = λ/a
where,
θ = angular resolution of Cat's eye = ?
λ = wavelength = 500 nm = 5 x 10⁻⁷ m
a = slit width of eye = 0.5 mm = 5 x 10⁻⁴ m
Therefore,
θ = (5 x 10⁻⁷ m/5 x 10⁻⁴ m)
Therefore,
θ = 0.001
θ = Sin⁻¹(0.001)
θ = 0.001 rad = 1 x 10⁻³ rad
Hence, the correct answer is:
C. 10⁻³ rads
which of the following calls one might hear a refree make?
A) Strike
B) Foul
C) Safe
D) All of the above
Answer: D) All of the above
Explanation:
A driver of a car going 40 m/s (approx. 90 mph) suddenly sees the lights of a barrier 40.0 m ahead. It takes the driver 0.75 s before he applies the brakes (this is known as reaction time). Once he does begin to break the decelerates at a rate of 10.0 m/s^2 (Be careful of signs). Does he hit the barrier?
Answer:
Explanation:
Distance of barrier = 40 m
Distance covered during reaction time = .75 x 40 = 30 m .
distance covered during deceleration can be calculated as follows .
v² = u² - 2 a s
0 = 40² - 2 x 10 x s
s = 80 m
Total distance covered before coming to rest = 30 + 80 = 110 m
Distance of barrier = 40 m , so it will hit the barrier .
Which change of state is shown in the model?
-condensation
-deposition
-boiling
-freezing
Answer: deposition
Explanation:
Try process of elimination. We know it's not boiling because that is basically water turning into gas. It's not condensation because it's not water which collects as droplets on a cold surface when humid air is in contact with it.
Answer:
deposition
Explanation:
You stand on a merry-go-round which is spinning at f = 0.25 revolutions per
second. You are R = 200 cm from the center.
(a) Find the angular speed ω at which it is spinning.
[3 marks]
(b) Find the centripetal acceleration, ac with which it is spinning. [3 marks]
(c) What is the minimum coefficient of static friction µs between your shoes and
the floor that will keep you from slipping off?
[4 marks]
Answer:
(a) ω = 1.57 rad/s
(b) ac = 4.92 m/s²
(c) μs = 0.5
Explanation:
(a)
The angular speed of the merry go-round can be found as follows:
ω = 2πf
where,
ω = angular speed = ?
f = frequency = 0.25 rev/s
Therefore,
ω = (2π)(0.25 rev/s)
ω = 1.57 rad/s
(b)
The centripetal acceleration can be found as:
ac = v²/R
but,
v = Rω
Therefore,
ac = (Rω)²/R
ac = Rω²
therefore,
ac = (2 m)(1.57 rad/s)²
ac = 4.92 m/s²
(c)
In order to avoid slipping the centripetal force must not exceed the frictional force between shoes and floor:
Centripetal Force = Frictional Force
m*ac = μs*R = μs*W
m*ac = μs*mg
ac = μs*g
μs = ac/g
μs = (4.92 m/s²)/(9.8 m/s²)
μs = 0.5
What happens when a charged balloon is brought close to a wall?
The balloon becomes negatively charged.
The charges in the wall rearrange themselves.
The wall and the balloon repel each other.
The wall becomes negatively charged.
Answer:
a the balloon becomes negatively charged
When a charge balloon brought closer to the wall, they will repel each other. Option C is correct.
Electric Charge:
It shows the degree at which the atom or object has less or more electron than proton.
An atom with extra electrons than proton has negative charge while atoms will less electron than proton has positive charge.
Opposite charge always attracts while similar charges repel each other. Since both wall and balloon are negatively charged.
Therefore, when a charge balloon brought closer to the wall, they will repel each other.
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