A roller coaster car sits on a peak. Just before it moves down the track, the car's potential energy is 10,000 joules. Halfway down the hill, its potential
energy decreases to 4,000 joules. What is the work done by the car to reach
this point? Assume that the track has negligible friction.

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d

Atruck travels at an average speed of 70 km/hr. if it travels 100 km in the first hour, how far will it go the second hour of a 2 hour trip? if you could also give me the steps that would great.