A box of weight W is pulled by a force P along a slope. The length of the slope is d, and the box rises a height h. The frictional force between the box and the slope is F. The diagram shows the directions of the forces. [Figure 15.1] The purpose of the slope is to raise the box vertically. Which expression gives the efficiency of the slope?

An old-fashioned 60 W lamp converts 95% of its energy supply into heat. A 4.0 W modern lamp has the same power output…

A small diesel engine uses a volume of 1.5 × 10⁴ cm³ of fuel per hour to produce a useful power output of 40 kW. It m…

Which statement best represents the principle of conservation of energy?

Define gravitational potential at a point.

The pressure p of an ideal gas having density ρ is given by the expression p = ⅓ ρ⟨c²⟩.

State three features of the orbit of a geostationary satellite.