State the type of energy transformation in the following cases: $(a)$ in a loudspeaker $(b)$ solar battery.

Calculate the kinetic energy of a body of mass $2 \, kg$ moving with a velocity of $0.1 \, m s^{-1}$. (in $, J$)

An object of mass $1 \, kg$ has a potential energy of $1 \, J$ relative to the ground when it is at a height of: (in $, m$)

$A$ girl is carrying a school bag of $3 \, kg$ mass on her back and moves $200 \, m$ on a levelled road. The work done against the gravitational force will be $(g = 10 \, m \, s^{-2})$.

What is the amount of work done by a force when a body moves in a circular path?

Calculate the amount of work done in moving a $50 \, kg$ mass through a distance of $10 \, m$ by applying a force of $100 \, N$. (in $, J$)