In case of negative work,the angle between the force and displacement is: (in $^o$)

How much work is done by a weight lifter when he holds a weight of $80 \,kg$ on his shoulders for two minutes?

Name at least six forms of energy.

$(a)$ Define average power. Calculate the total energy consumed in the month of November in a household in which four devices of power $500\, W$ each are used daily for $10\, hours.$
$(b)$ $A$ freely falling object eventually stops on reaching the ground. What happens to its energy?

Define work. Write an expression for work in terms of force and displacement. State the $SI$ unit of work done.

What type of energy is stored in the spring of a watch?