Work and Energy...

A 220 V, 100 W bulb is connected to a 110 V source. Calculate the power consumed by the bulb.

A girl of mass 40 kg climbs 50 stairs of average height 20 cm each in 50 s. Find the power of the girl. $$(g = 10 m\:s^{-2})$$

If an electric iron of $$1200 \ W$$ is used for $$30 \ minutes$$ everyday, find electric energy consumed in the month of April.

   Answer question numbers 72 and 73 based on the following information.
Solar surface radiates energy uniformly at a rate of $$4 \times  10^{26}W$$. This energy spreads or distributes uniformly and normally outwards.

72. Considering Earth and the Sun to be spherical object, the amount of radiant energy received by the Earth per second is nearly

A girl having a mass of $$35\ kg$$ sits on a trolley of mass $$5\ kg$$. The trolley is given an initial velocity of $$4\ ms^{-1}$$ by applying a force. The trolley comes to rest after traversing a distance of $$16\ m$$. How much work is done on the trolley? 

 In a hydro power plant:

How much work they do in just holding it ?

$$1kWh= $$ _________?

Kilowatt is the unit of electrical _______ but kilowatt-hour is the unit of electrical _______.

An 800 g ball is pulled up a slope as shown in the diagram. Calculate the potential energy it gains.