how much gravitational potential energy does a 165kg roller coaster car have when it is at the top of a hill 42 meters above the ground?​

What is a costume plot? why is it important to a film or theater production?

At what time will the interfering waves have an amplitudeof zero?

Calculate the first and second velocities of the car with four washers attached to the pulley, using the formulas v1 = 0.25 m / t1 , and v2 = 0.25 m / (t2 – t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. record these velocities, to two decimal places, in table e.