Is it possible that an object is in a state of accelerated motion due to an external force acting on it,but no work is being done by the force? Explain with an example.

$A$ light and a heavy body have the same momentum. Which one will have greater kinetic energy?

$(a)$ The Earth,moving around the Sun in a circular orbit,is acted upon by a force,and hence work must be done on the Earth by the force. State whether the statement is correct or not. Give reasons for your answer.
$(b)$ $A$ coolie holding a heavy box is waiting at the bus stand for $15$ minutes. How much work is done by him?
$(c)$ $A$ man weighing $70 \, kg$ carries a weight of $10 \, kg$ to the top of a tower $100 \, m$ high. Calculate the work done by the man. $(g = 10 \, m s^{-2})$

Define power. Write the commercial unit and $SI$ unit of electrical energy. An electrical geyser of $1.5 \, kW$ works for $2$ hours. Find the electrical energy units consumed in a day.

$A$ man rowing a boat upstream is at rest with respect to the shore. Is he doing work?

$A$ person is holding a bucket by applying a vertical force of $10 \,N$. He moves a horizontal distance of $5 \,m$ and then climbs up a vertical distance of $10 \,m$. Calculate the total work done by him. (in $J$)