What was the velocity of a dog that ran 50 meters in 15 seconds?
2 answers:
You might be interested in
<h2>Answer: 12.24m/s</h2>
According to <u>kinematics</u> this situation is described as a uniformly accelerated rectilinear motion. This means the acceleration while the car is in motion is constant.
Now, among the equations related to this type of motion we have the following that relates the velocity with the acceleration and the distance traveled:
(1)
Where:
is the Final Velocity of the car. We are told "the car comes to a stop after travelling", this means it is 0.
is the Initial Velocity, the value we want to find
is the constant acceleration of the car (the negative sign means the car is decelerating)
is the distance traveled by the car
Now, let's substitute the known values in equation (1) and find :
(2)
(3)
Multiplying by -1 on both sides of the equation:
(4)
(5)
Finally:
>>>This is the Initial velocity of the car
The work done by the friction force to stop the player is equal to his loss of kinetic energy:
The work done by the friction force is the magnitude of the force
times the distance covered by the player, d:
The loss in kinetic energy is simply equal to the initial kinetic energy of the player, since the final kinetic energy is zero (the player comes to rest):
Substituting into the first equation, we get:
from which we find d, the distance covered by the player:
The work done by the friction force is the magnitude of the force
The loss in kinetic energy is simply equal to the initial kinetic energy of the player, since the final kinetic energy is zero (the player comes to rest):
Substituting into the first equation, we get:
from which we find d, the distance covered by the player: