You are on a train traveling east at speed of 19 m/s with respect to the ground. 1)If you walk east toward the front of the trai
1 answer:
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Answer:
(a)
(b)
Explanation:
The average power is defined as the amount of work done during a time interval:
According to work-energy theorem, the work done is equal to the change in kinetic energy. So, we have:
Recall that the weight is given by:
The car accelerates uniformly from rest (). Replacing (3) in (2), we have:
(a) Finally, we replace this in (1):
(b)
The motor does 20 J of work on the block, it means that the total mechanical energy of the block has increased by 20 J. But the increase in total mechanical energy is equal to the sum of the increases in potential energy and kinetic energy:
So, if the gravitational potential energy has increased by 15 J, the kinetic energy has increased by
So, if the gravitational potential energy has increased by 15 J, the kinetic energy has increased by