Akg object has 400 j of potential energy. find how high off the groumd the object is

An electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field

An athlete is holding 24 lb of weights at a height of 6 inches above the stack as shown. to lower the weights, she applies a constant force of 5 lb to the handle. determine the velocity of the weights immediately before they hit the stack.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.