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
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
A man steps off a diving platform lands in the water below. If he were to miss the water and land on the concrete, his change in momentum would be the same as if he landed in the water. Why is the change in momentum the same for both situations?
Answer:
if he were to land on concrete, he would most likely die and stop all momentum and for the water, he'd most likely live/die (mostly live) and slow momentum to a stop and rise up to the surface
Explanation:
that's the explanation now i gotta execute order 66
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.
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:
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.
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:
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
1. A curious physics student drops a book from a high building.
A. What is the VELOCITY of the brick after 3.0s?
B. How FAR(Distance) does the book fall during this time?
2. Suppose a free-fall ride at an amusement park starts at a rest and then drops.
A. What is the VELOCITY of the ride after 2.5s?
B. How FAR do people on the ride fall during the 2.5s time period?
3. You throw a ball downward from a window at a speed of 3.0 m/s.
A. How FAST will it be moving when it hits the sidewalk 2.0m below?
4. If I drop a photo copier off of a 45m tall building and splats on the ground below:
A. Calculate the TIME to hit the ground:
B. Calculate the VELOCITY just before:
Answer:
1.
A. Vf = 29.4 m/s
B. h = 44.1 m
2.
A. Vf = 24.5 m/s
B. h = 30.625 m
3.
A. Vf = 5.5 m/s
4.
A. t = 3.03 s
B. Vf = 29.7 m/s
Explanation:
1.
A.
using 1st equation of motion:
Vf = Vi + gt
where,
Vf = Final Velocity = ?
Vi = Initial Velocity = 0 m/s (since, book starts from rest)
g = 9.8 m/s²
t = time = 3 s
Therefore,
Vf = 0 m/s + (9.8 m/s²)(3 s)
Vf = 29.4 m/s
B.
using 2nd equation of motion:
h = Vi t + (1/2)gt²
h = (0 m/s)(3 s) + (1/2)(9.8 m/s²)(3 s)²
h = 44.1 m
2.
A.
using 1st equation of motion:
Vf = Vi + gt
where,
Vf = Final Velocity = ?
Vi = Initial Velocity = 0 m/s (since, book starts from rest)
g = 9.8 m/s²
t = time = 2.5 s
Therefore,
Vf = 0 m/s + (9.8 m/s²)(2.5 s)
Vf = 24.5 m/s
B.
using 2nd equation of motion:
h = Vi t + (1/2)gt²
h = (0 m/s)(2.5 s) + (1/2)(9.8 m/s²)(2.5 s)²
h = 30.625 m
3.
A.
using 3rd equation of motion:
2gh = Vf² - Vi²
where,
Vf = Final Velocity = ?
Vi = Initial Velocity = 3 m/s
g = 9.8 m/s²
h = height = 2 m
Therefore,
2(9.8 m/s²)(2 m) = Vf² - (3 ms)²
Vf² = 39.2 m²/s² - 9 m²/s²
Vf = √30.2 m²/s²
Vf = 5.5 m/s
4.
A.
using 2nd equation of motion:
h = Vi t + (1/2)gt²
where,
h = height = 45 m
Vi = Initial Velocity = 0 m/s (since, photo copier was initially at rest)
t = time = ?
g = 9.8 m/s²
45 m = (0 m/s)(t) + (1/2)(9.8 m/s²)(t)²
t² = 2(45 m)/(9.8 m/s²)
t = √9.18 s²
t = 3.03 s
B.
using 1st equation of motion:
Vf = Vi + gt
Vf = 0 m/s + (9.8 m/s²)(3.03 s)
Vf = 29.7 m/s
How much work is done when you push a table with 300 N of force 5 m across a room?
A block of mass 500g is pulled from rest on ahorizontal frictionless bench by a steady force F and travels 8m in 2s find the acceleration?
We are Given:
Mass of the block (m) = 500 grams or 0.5 Kg
Initial velocity of the block (u) = 0 m/s
Distance travelled by the block (s) = 8 m
Time taken to cover 8 m (t)= 2 seconds
Acceleration of the block (a) = a m/s²
Solving for the acceleration:
From the seconds equation of motion:
s = ut + 1/2* (at²)
replacing the variables
8 = (0)(2) + 1/2(a)(2)²
8 = 2a
a = 4 m/s²
Therefore, the acceleration of the block is 4 m/s²
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 .
Give one suggestion how to increase the velocity of water rocket?
Answer:
Streamline the body of the rocket to reduce drag
Keep weight to a minimum
Use higher pressures
Use the right amount of water
An astronaut weighs 626 newtons at Earth's surface. If he were to cut his distance from
Earth's center in half, what would be his new weight, to the nearest newton?
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!
what is the mass of the 40 kg object on the moon?
Answer:
6.64 Newtons
On the moon that 40 kg child would have a weight of 6.64 Newtons (kg multiplied by gravity) because the moon's gravity is 1/6th of the Earth's gravity. Your mass on any planet on the solar system (Jupiter, Venus, Earth, or anywhere else) is the same because the amount of matter in you does not change.
Explanation:
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.
How long would it take light to travel round trip to Mars when it is 2x1010m from the Earth?
a) 0.015s
b) 0.03s
c) 66.7s
d) 133s
Show calculation
Answer:
66.7s
Explanation:
Given parameters:
Distance between Mars and Earth = 2 x 10¹⁰m
Unknown:
Time it takes for light to travel = ?
Solution:
The speed of light is given as 3 x 10⁸m/s
Now;
Speed = [tex]\frac{distance}{time}[/tex]
Time = [tex]\frac{distance}{speed}[/tex]
Insert the parameters and solve;
Time = [tex]\frac{2 x 10^{10} }{3 x 10^{8} }[/tex] = 66.7s
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 :)
To overcome an object's inertia, it must be acted upon by __________. A. gravity B. energy C. force D. acceleration
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
help me please answer this
Answer:
that's fusion
Explanation:
Answer:
the answer is fusion for this
Help me , what is the properties of fluids ?
The properties of fluids are Density,Viscosity,Temperature, Pressure,Specific Volume,Specific Weight,Specific Gravity.
A 2.00 kg mass is located at (4.00 m, 0.00 m, 0.00 m) and a 4.00 kg mass is located at (0.00 m, 3.00 m, 0.00 m). If this system of masses rotated about the Z-axis perpendicular to the X-Y plane, then the moment of inertia of this system is:_______
Answer:
The moment of inertia of this system is 68 kilogram-square meters.
Explanation:
We have two particles rotating about the z-axis, which is orthogonal to xy plane, the moment of inertia of the system ([tex]I_{z}[/tex]), measured in kilogram-square meters, is determined by the following formula:
[tex]I_{z} = \Sigma \limits_{i=1}^{2}m_{i}\cdot r_{i}[/tex] (1)
Where:
[tex]m_{i}[/tex] - Mass of the i-th particle, measured in kilograms.
[tex]r_{i}[/tex] - Distance of the i-th particle from axis of rotation, measured in meters.
By Pythagorean Theorem we calculate each distance:
[tex](x_{1}, y_{1}, z_{1}) = (4\,m, 0\,m,0\,m)[/tex]
[tex]r_{1}=\sqrt{(4\,m-0\,m)^{2}+(0\,m-0\,m)^{2}+(0\,m-0\,m)^{2}}[/tex]
[tex]r_{1} = 4\,m[/tex]
[tex](x_{2},y_{2}, z_{2}) = (0\,m, 3\,m, 0\,m)[/tex]
[tex]r_{2} = \sqrt{(0\,m-0\,m)^{2}+(3\,m-0\,m)^{2}+(0\,m-0\,m)^{2}}[/tex]
[tex]r_{2} = 3\,m[/tex]
If we know that [tex]m_{1} = 2\,kg[/tex], [tex]r_{1} = 4\,m[/tex], [tex]m_{2} = 4\,kg[/tex] and [tex]r_{2} = 3\,m[/tex], then the moment of inertia of the system is:
[tex]I_{z} = m_{1}\cdot r_{1}^{2}+m_{2}\cdot r_{2}^{2}[/tex] (1b)
[tex]I_{z} = (2\,kg)\cdot (4\,m)^{2}+(4\,kg)\cdot (3\,m)^{2}[/tex]
[tex]I_{z} = 68\,kg\cdot m^{2}[/tex]
The moment of inertia of this system is 68 kilogram-square meters.
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
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
You accidentally drop a watch from the roof of a six-story building. While picking up the watch , you notice that it stopped 2s after it was dropped. How tall is the building?
Answer:
20 m
Explanation:
Area under the speed-time graph = Distance Traveled
Area under Graph 1/2(2)(20)
=20 m
A 20kg block slides a cross a horizontal surface. If the coefficient of kinetic friction between the block and the surface is 0.20, what is the force of kinetic friction that acts on the block?
Compute the block's weight:
w = m g = (20 kg) (9.8 m/s²) = 196 N
The net vertical force is 0, so the normal force has the same magnitude:
n + (-w) = 0 → n = 196 N
The frictional force (mag. f ) is proportional to the normal force by a factor of µ = 0.20 such that
f = 0.20 (196 N) = 39.2 N ≈ 39 N
The force of kinetic friction acting on the block of mass 20 Kg having a coefficient of kinetic friction of 0.2 is 39.2 N
We'll begin by calculating the the normal reaction (N). This can be obtained as follow:Mass (m) = 20 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal reaction (N) =?N = mg
N = 20 × 9.8
N = 196 NFinally, we shall determine the force of kinetic friction. This can be obtained as follow:Coefficient of kinetic friction (µ) = 0.2
Normal reaction (N) = 196
Force of kinetic friction (F) =?F = µN
F = 0.2 × 196
F = 39.2 NTherefore, the force of kinetic friction acting on the block is 39.2 N
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Nicolas is playing with his toy car. A parachute in the back of the car is released to help slow down the car.
If the forces act on the car as shown in the picture, what is the net force?
Answer:3 N —->
Explanation:
In the case when the forces act on the car as shown in the picture so here the net force should be 3N.
Calculation of the net force:Since
A parachute in the back of the car is released to help slow down the car.
So here the net force should be
= 10 N - 7N
= 3 N
Hence, In the case when the forces act on the car as shown in the picture so here the net force should be 3N.
Learn more about force here: https://brainly.com/question/21422036
Plz help ASAP I will give brainliest PLZ
The weight of a bucket is 186 N. The bucket is being raised by two ropes. The free-body diagram shows the forces acting on the bucket.
A free body diagram with 3 force vectors. The first vector is pointing downward, labeled F Subscript g Baseline = 186 N. The second vector is pointing up, labeled F Subscript 1 Baseline 105 N. The third vector is pointing upward from the tip of the second using the tail to tip method, labeled F Subscript 2 Baseline = 115 N. The combined two vectors pointing upward are shorter than the one pointing downward.
The acceleration of the bucket, to the nearest tenth, is
m/s2.
Answer:
1.8m/s^2
Explanation:
Since the two ropes are going up, their combined force is 105+115=220N. With a gravitational force of 186N, the force of the two ropes pulling up the will be 220-186=34N.
Now we need the mass of the bucket itself in order to find the acceleration of the bucket (remember that F=ma and m is needed to find a). Since gravitational acceleration is 9.8m/s^2 and F=186N, 186/9.8=18.97959184 kg for the mass of the bucket.
Now that we have the mass of the bucket, we can find the acceleration of the bucket. Since F=34N from earlier, 34N/18.97959184kg=1.791397849m/s^2=1.8m/s^2 is the acceleration of the bucket.
Therefore, 1.8m/s^2 is the correct answer.
Please mark brainliest!
Answer:
1.8
Explanation:
honestly i jus took the test
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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