Question 1 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2b5f59b460d7261f610.JPG' /> In the given figure, a boy is moving on a straight road against a frictional force of 5 N. After travelling a distance of 1.5 km he forgot the correct path at a round about of radius 100m. However, he moves on the circular path for one and half cycle and then he moves forward upto 2.0 km. Calculate the work done by him.

Question 2 :
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?

Question 3 :
An electric heater is rated 1500 W. How much energy does it use in 10 hours?

Question 4 :
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 5 :
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 6 :
The energy used in one hour at the rate of 1kW is called 1 kW h. TRUE OR FALSE?

Question 7 :
Compare the power at which a 250 g squirrel climbing up on a tree at a rate of $0.5 ms^{–1}$ is moving upwards against the force of gravity. $(given g = 10 ms^{–2})$

Question 8 :
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and final points of the object lie on the same horizonta line. What is the work done by the force of gravity on th object

Question 9 :
A girl having mass of 35 kg sits on a trolley of mass 5 kg. The trolley is given an initial velocity of $4 ms^{–1}$ by applying a force. The trolley comes to rest after traversing a distance of 16 m. How much work is done by the girl?

Question 10 :
The kinetic energy of an object of mass, m moving with a velocity of 5 m $s^{-1}$ is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?