A garage hoist lifts a truck up $4$ meters above the ground in $30$ seconds. Find the power delivered to the truck. [Given: $1000$ kg as the mass of the truck]

Pratyush can run at a speed of $8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ against the frictional force of $10 \mathrm{N}$. His friend Adarsh can move at a speed of $3 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ against the frictional force of $25 \mathrm{N}$. Who is more powerful and why?

An electric oven of $3 \mathrm{kW}$ is connected to the mains of $220 \mathrm{V}$. Calculate:

The cost of electrical energy consumed if the cost per unit is $\mathrm{Rs}. 6.50$ and if the oven is switched on for an hour.