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.

2,191.

A piece of brass of mass 170kg has its temperature raised from 0oC to 30oC. Calculate its increase in volume, given the density of brass at 0oC as 8.5 x 103kgm3 and its cubic expansivity as 5.7 x 10-1k1

A.

3.4 x 10-5m3

B.

4.3 x 10-5m3

C.

3.4 x 10-5m3

D.

3.4 x 10-3m3

E.

3.4 x 10-2m3

Correct answer is C

V = \(\frac{m}{p}= \frac{170}{8.5 x 10^{-3}}\) = 0.02

= \(\Delta\)\(\frac{\delta V}{V \delta T}\)

\(\delta V\) = \(\Delta\) x V x \(\delta\)T

= 5.7 x 10-5 x 0,02 x 30

= 0 3.42 x 10-5

2,192.

The lower and upper fixed points of a mecury-in-glass thermometer are marked Y and 180mm respectively. On a particular the mecury meniscus in the thermometer rises to 45mm. If the corresponding reading on a scale is 10o, calculate the value of Y.

A.

4mm

B.

18mm

C.

30mm

D.

135mm

E.

450mm

Correct answer is C

by interpolation,

\(\frac{100 - 0}{10- 0} = \frac{180 - y}{45 - y}\)

\(\frac{100}{10} = \frac{180 -y}{45 - y }\)

450 - 10y = 180 - y 

- 9y = - 270 

y = 30mm

 

2,193.

An object is heated from 30°C to 57°C. The increase in its temperature on the Kelvin scale is

A.

17k

B.

27k

C.

81k

D.

246k

E.

300k

Correct answer is B

30°C + 273 = 303K

57°C + 273 = 330K

∆T = 330K - 303K

→ 27K

2,194.

A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of 2m-1 and rebounds with the same speed. Determine the impulse experienced by the ball

A.

20.0kgm-1

B.

5.0kgm-1

C.

1.3kgm-1

D.

0.0kgm-1

E.

10.0kgm-1

Correct answer is A

No explanation has been provided for this answer.

2,195.

The earth is not a perfect sphere because its equatorial axis is longer than the polar axis. where on the earth's surface would an object have its greatest weight?

A.

half way between the equator and the north pole

B.

near the equator

C.

half way between the equator and the south pole

D.

at either pole

E.

at the equator

Correct answer is C

No explanation has been provided for this answer.