A girl drops a ball from the top of a building. If the ball takes 5 s to reach the floor, what is the height of the building? (Take g = 10 m/s²)

• 25 m
• 50 m
• 125 m
• 250 m

A wooden box is pushed across a rough surface with constant speed of 2 m/s. Which statement is correct?

• The frictional force decreases as the block moves at constant speed.

• The frictional force increases as the block moves at constant speed.

• The frictional force is equal to the pushing force.

• The frictional force is less than the pushing force.

When solid A of mass 5 g is immersed in a measuring cylinder with water, it displaces the same volume of water as solid B of mass 10 g. What can be deduced about the densities of solids A and B?

• Both A and B have the same density.

• Density of A is half of B.

• Density of A is four times that of B.

• Density of A is twice of B.

Consider a thin rectangular wooden ruler. What happens to the position of the centre of gravity if a small piece of the wood gets chipped off at one corner of the ruler?

• It cannot be determined.

• It will move away from the chipped corner.

• It will move towards the chipped corner.

• It will not shift.

Which one of the following statements about the pressure caused by a force acting on an area, is not correct?

• A larger area will produce a smaller pressure.

• As the area gets smaller, the pressure increases.

• The greater the area, the greater the pressure.

• The greater the force, the greater the pressure.

A car is accelerating on a level road and acquires a velocity twice of its initial velocity. What happens to the gravitational potential energy of the car during this process?

• It becomes half of the initial gravitational potential energy.

• It becomes twice of the initial gravitational potential energy.

• It becomes 4 times the initial gravitational potential energy.

• It does not change.

Some oxygen gas is contained in a sealed container that has a constant volume. What will happen to the oxygen molecules when the gas is heated?

• They will expand.

• They will become denser.

• They will move closer to each other.

• They will move more quickly.

A box of weight 5 N is pushed along the table surface with a 4 N force. It moves a distance of 2 m along the table. What is the work done on the box?

• 2 N

• 4 N

• 8 N

• 10 N

Which of the following shows in descending order, the kinetic energy of a substance in different states?

• gas, liquid, solid

• gas, solid, liquid

• solid, gas, liquid

• solid, liquid, gas

Radiation is the transfer of heat by means of ……………………..

• electrical wave.

• electromagnetic waves.

• magnetic wave.

• sound waves.