Consider the 18-speed bicycle with 21cm cranks and 45cm wheels. If the sprockets at the crank and the rear drive wheel are the same size, then calculate the ratio of the output force on the tire to the input force on the on the pedal.

Two boys are carrying a load of 900N on a stick between them. The length of the stick from the load to  one end is 2m and the length from the load to the other end is 3m. Calculate what part of the load each boy carries.

The moment of a force is called

What are the two variables which determine the mechanical advantage of a simple machine?

A force of 10N rotates a body in the anti-clockwise direction. The arm of the body is 10cm. What is the moment of force?

When a person opens a door, he applies

A 3.0-kg ball and a 1.0-kg ball are placed at opposite ends of a massless beam so that the system is in equilibrium as shown. Note: The drawing is not drawn to scale. What is the ratio of the lengths, b/a?

How much effort is required for lifting a load of 1000N with the help of wheel and axle when the radius of the wheel is 50cm and that of the axle is 10cm.

The ratio of the work output to the work input is ______________.

Calculate the effort required to raise a 100kg anchor on to a boat with a wheel and axle of radii 50cm and 10cm respectively.