In a loading a lorry a man lifts boxes each weight 200N through a height of 3.5m. a). How much work does he do in lifting one box?
b). How much energy is transferred when one box is lifted?
c). If he lifts four boxes per minute at what power is he working?

If a spring has a k value of 100 newtons per meter and it is stretched 0.50 meters, what is the restoring force of the spring?

Which is special about a dc circuit ? a. it has both series and parallel components b. it has only series or only parallel components c. charge moves in a single direction d. charge moves back and forth quickly

Adiver named jacques observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm) to the surface (where the pressure is 1.00 atm). the temperature at the bottom is 4.00 ∘c, and the temperature at the surface is 23.0 ∘c.what is the ratio of the volume of the bubble as it reaches the surface (vs) to its volume at the bottom (vb)? if jaques were to hold his breath the air in his lungs would be kept at a constant temperature. would it be safe for jacques to hold his breath while ascending from the bottom of the lake to the surface?