Circular Motion, Work and Energy

Centripetal force and acceleration, work, and the conservation of mechanical energy.

12 questions, free, marked as you go with a worked explanation on every one.

What this covers

A car rounds a bend of radius 25 m at a steady 10 m/s. What is its centripetal acceleration?
A 1200 kg car takes a curve of radius 45 m at 15 m/s. What centripetal force is needed to keep it on the road?
A ball is whirled on a string at constant speed in a horizontal circle. Which statement is correct?
How much work does the centripetal force do on an object in uniform circular motion over one full revolution?
A 50 N force pushes a crate 8.0 m in the direction of the force. How much work is done?
The same 50 N force moves a crate 8.0 m, but now acts at 60° to the direction of motion. How much work is done?
What is the kinetic energy of a 2.0 kg ball travelling at 6.0 m/s?
A 3.0 kg book is lifted onto a shelf 4.0 m above the floor. How much gravitational potential energy does it gain? Use g = 9.81 m/s².
A stone is dropped from rest at a height of 20.0 m. Ignoring air resistance, how fast is it moving just before it lands? Use g = 9.81 m/s².
In an isolated system with no friction, which statements are true? Select all that apply.
An object moves in a circle of radius 4.0 m, completing one revolution every 2.0 s. What is its speed?
Use the table. At which height is all of the car's mechanical energy kinetic?