Physics Form 4 (Chapters 1, 2 & 3)

Which of the following is a S.I. base unit?

• Joule

• Tesla

• Newton

• Candela

Answer explanation

Candela (cd) is the bbase unit for luminous intensity.

The diagram shows a graph of relationship between p and q.

Which of the following is incorrect?

• p increases linearly with q

Which of the following graph shows P varies non-linearly with V?

• 
• 
• 
• 

Answer explanation

Curve with positive gradient and passive through the origin.

A dart leaves the barrel of a blow pipe of length 1.5m at a speed of 20 ms‐¹. Estimate the time taken for the dart to travel in the barrel?

• 0.10s

• 0.15s

• 0.20s

• 0.25s

Answer explanation

s= ½(u + v)t

1.5=½(0+20)t

t=0.15s

Diagram shows a displacement-time graph of a toy car.

What is the average velocity of the toy car?

• 0.5ms-¹

• 1.0ms‐¹

• 1.5ms-¹

• 2.0ms-¹

Answer explanation

Average velocity

= Total displacement

Total time taken

= 10

20

= 0.5ms-¹

An entertainer jerks a table cloth without moving the objects on the table.

This situation is explained by............ .

• Newton's First Law of Motion

• Newton's Second Law of Motion

• Newton's Third Law of Motion

• Newton's Universal Law of Gravitation

Answer explanation

The larger the mass of an object, the larger the inertia of the object.

The diagram shows a long jump athlete bending his legs and landing safely.

What is the factor that affects this situation?

• The acceleration is huge.

• The change of velocity is big.

• The change of momentum is big.

• The time of action of the force is bigger.

Answer explanation

Impulsive force is the rate of change of momentum in a collision or impact in a short duration of time. If changein momentum, mv - mu is constant, then F ¤ 1/t.

If t is longer, the magnitude of F is small.

Kylo's weight on the Moon is 750N.

What will happen to his weight back on the Earth?

• Increases 6 times

• Decreases 6 times

• Unchanged

• Becomes very heavy

Answer explanation

Weight,W = mg,

g _earth / 6g_moon

Hence W increases 6 times