Question 1 :
A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force?

Question 3 :
Avinash can run with a speed of $8 ms^{-1}$ against the frictional force of 10 N, and Kapil can move with a speed of $3 ms^{–1}$ against the frictional force of 25 N. Who is more powerful and why?

Question 4 :
The energy used in one hour at the rate of 1kW is called 1 kW h. TRUE OR FALSE?

Question 6 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2e1f59b460d7261f64a.png' /> Look at the above image. In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero resctively.

Question 7 :
Find the energy in kWh consumed in 10 hours by four devices of power 500 W each.

Question 8 :
The kinetic energy of an object of mass m moving with a velocity of 5 $\frac{m}{s}$ is 25 J. What will be its kinetic energy when its velocity is increased three times?

Question 9 :
Find the energy in kW h consumed in 10 hours by four devices of power 500 W each.

Question 10 :
An object of mass m is moving with a constant velocity v. How much work should be done on the object in order to bring the object to rest?

Question 19 :
A __________ is a group of two or more atoms that are chemically bonded together, that is, tightly held together by attractive forces.