Jasvinder Kaur Randhawa Solutions for Exercise 2: TEST YOUR SKILLS

What is the commercial unit of energy? Define it.

Give one example where work done on an object is negative.

What work is said to be done(in joules) to increase the velocity of a car from $15 \mathrm{km}/\mathrm{h}$ to $30 \mathrm{km}/\mathrm{h}$, if the mass of the car is $1000 \mathrm{kg}$? (Choose from: $26041.67/ 2604.16/ 260416.70$)

(Give answer with two decimals and answer should contain only magnitude).

A body possesses potential energy of $460 \mathrm{J}$ whose mass is $20 \mathrm{kg}$ and is raised to a certain height. The magnitude of height is _____ metre. $(g=10 \mathrm{m}/{\mathrm{s}}^2)$ (Choose From: $3.2, 2.3, 4.8$)

An electric appliance of $100 \mathrm{W}$ is used for $3$ hours per day. Calculate the units of energy consumed for a month.
(Solution should contain only magnitude).

Derive the formula of kinetic energy.

With pendulum as an example explain the law of conservation of energy.

Derive the formula for potential energy.