Velocity adds direction to speed; it is the rate of travel in a particular direction. To calculate velocity, divide distance traveled by the time it took to travel that distance and add direction. If one's position does not change, velocity is zero.
In this process, gravitational potential energy is converting into heat/thermal energy.
In fact, the skier starts at a certain height h, so it has gravitational potential energy equal to

as he slides down, he loses this energy. However, the problem says that the speed of the skier remains constant during the motion, so this energy is not converting into kinetic energy, which remains constant. The only possibility is that a frictional force between the skier and the ice is acting on the skier. When the friction acts, the energy of the skier is converted into motion of the molecules of the ice, heating it, so into thermal energy.
Answer:
Your answer should be B.
If your internal energy or <em><u>heat</u></em> of a system <em><u>decreases</u></em> then you know that you are taking that energy out and doing <em><u>work.</u></em>
Answer:
Average acceleration is 2.5 m/s^2.
Explanation:
Average acceleration can be found by dividing the change in speed by the change in time.
We know that the initial velocity=10m/s, the final velocity=30m/s and time elapsed is t=8s.
a= (Final velocity-Initial Velocty)/t
a=(30-10)/8=20/8=2.5 m/s^2