Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

846.

A uniform bar AB is balanced on a knife-edge which is 60cm from B by a mass of 22g which hangs at C 10cm from A. Calculate the mass of the bar.

A.

133.2g

B.

66.0g

C.

60.0g

D.

22.0g

Correct answer is B

clockwise movement = anticlockwise movement

w x 10 = 22 x 30

w = \(\frac{22 \times 30}{10}\)

w = 66.0g

847.

A bullet fired vertically upwards reaches a height of 500m. Neglecting air resistance, calculate the magnitude of the initial velocity of the bullet. [g = 10ms-2]

A.

500.0ms-1

B.

100.0ms-1

C.

70.0ms-1

D.

50.0ms-1

Correct answer is B

V2 = U2 + 2gs

V2 = 0

V2 = 2gs

h = 500m

g = 10ms-2

V2 2 x 10 x 500

V2 = 10,000

V = \(\sqrt{10000}\)

V = 100ms-1

848.

Two strings each inclined at an angle 30o to the horizontal are used to hold a bucket of water weighing 20N. Calculate the tension i n each string

A.

20 (\sqrt{3}\)N

B.

20N

C.

10 (\sqrt{3}\)N

D.

10N

Correct answer is B

No explanation has been provided for this answer.

850.

Which of the following statements describes a body in a stable equilibrium correctly?

A.

a person walking on a tight-rope

B.

ball on a smooth horizontal table

C.

ball resting on an inverted hemisphere bowl

D.

ball in the middle of a nemispherical bowl

Correct answer is D

No explanation has been provided for this answer.