$A$ $1 \, kg$ mass has a kinetic energy of $1 \, J$ when its speed is: (in $, m/s$)

State whether the following statement is true or false:
The rate of doing work is called power.

$A$ boy of mass $40 \, kg$ runs up a flight of $50$ steps,each $10 \, cm$ high,in $5 \, s$. Find: $(i)$ the work done by the boy,and $(ii)$ the power developed. $(g = 9.8 \, m s^{-2})$

$A$ body is falling from a height $h$. After it has fallen a height $\frac{h}{2}$,it will possess

The $CGS$ unit of work is:

An iron sphere of mass $10 \, kg$ has the same diameter as an aluminium sphere of mass $3.5 \, kg$. Both spheres are dropped simultaneously from a tower. When they are $10 \, m$ above the ground,they have the same