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.

2,446.

250g of lead at 170oC is dropped into 100g of water at 0oC. If the final temperature is 12oC, the specific heat of lead is (specific heat of water is 4,200J/kgoC)

A.

39.5J/kgoC

B.

50.4J/kgoC

C.

127.6J/kgoC

D.

154.6J/kgoC

E.

173.4J/kgoC

Correct answer is C

Heat lost = heat gained

0.25 x C1 x (170 - 12) = 0.1 x 4200 x (12 - 0)

C1 = 127.6J/kgoC

2,447.

Which of the following statements is NOT true? Thermostats are used to control the temperature of

A.

pressure cookers

B.

laundry irons

C.

hot water storage tanks

D.

aquaria for tropical fish

E.

heated apartments

Correct answer is A

No explanation has been provided for this answer.

2,448.

The accurate measurement of the relative density of substances in powder or granular form can be done using a beam balance and a

A.

pipette

B.

burette

C.

measuring cylinder

D.

density

E.

bottle

Correct answer is E

No explanation has been provided for this answer.

2,449.

Which of the following machines does NOT apply the lever principle?

A.

claw hammer

B.

wheel barrow

C.

single moving pulley

D.

sugartongs

E.

nutcrackers

Correct answer is C

No explanation has been provided for this answer.

2,450.

A mango fruit drops from a branch 10m above the ground, just before hitting the ground its velocity is (g = 10ms-2)

A.

10√2ms-1

B.

10ms-1

C.

100ms-1

D.

5√2ms-1

E.

200ms-1

Correct answer is A

Using, V2 = U2 + 2gs

V2 = 02 + (2 x 10 x 10)

V = 10√2ms-1