Other Physics Answers

5. a) Define viscosity. 

b) A matter has a body-centered cubic unit cell with a length of 330 𝑝𝑚 along an edge

and a density of 8.57 𝑔 𝑐𝑚−3

. Calculate the atomic mass of the matter.

c) Find the total energy of a moving object of mass 6.3 𝑘𝑔 and momentum

11.5 × 106 𝑘𝑔𝑚𝑠

−1

.

4. a) Define the elastic modulus. Explain the different types of elastic modulus.

b) State and explain Einstein's Photoelectric Effect theory.

c) If 12𝑁 force is applied to a fluid of cross-section 5.34 𝑐𝑚2 with a shearing rate of

0.7 𝑠

−1

then find the viscosity of the fluid.

3. a) Define crystal and unit cell 

b) Explain de Broglie wave and the photoelectric effect. 

c) A wire of length 7 𝑚 and radius 2.37 𝑚𝑚 is stretched by a load of 12370 𝑔𝑚 and

increased by 1.78% of the original length. Find the stress, strain, and Young’s

modulus of the material of the wire.

2. a) Define the surface tension and surface energy. 

b) Explain the elastic limit with an example. Draw the stress-strain curve for elasticity. 

c) A capillary tube with an inside radius of 638 𝑛𝑚 can support a 100 𝑚𝑚 column of

liquid that has a density of 820 𝑘𝑔𝑚−3

. The observed contact angle is 12.5°. Find

the surface tension of the liquid for ℎ = 20 𝑐𝑚.

1. a) Define elasticity of a matter. 

b) Define stress and strain. Explain different types of stress and strain. 

c) The radius of a silver bar is 30 𝑐𝑚. What force is required to stretch the bar by

12.7% of its length where Young’s modulus is 𝑌 = 7.25 × 1010 𝑁𝑚−2

.

a) Define elasticity of a matter. 1 b) Define stress and strain. Explain different types of stress and strain. 1+4 c) The radius of a silver bar is 30 𝑐𝑚. What force is required to stretch the bar by 12.7% of its length where Young’s modulus is 𝑌 = 7.25 × 1010 𝑁𝑚−2 . 

A shopper in a supermarket pushes a cart with a force of 35 N directed at an angle of 25° downward from the horizontal. Find the work done by the shopper on the cart as the shopper moves along a 50.0 m length of aisle.

If ΔT is the difference in temperature between a hot and a cold medium, the rate of heat transfer via conduction is proportional to ΔT to the power 

1

2

3

4

How much will a 1-km steel bridge expand due to a 10 K temperature change? 

1.2 m

12 cm

12 m

6 cm

5.0-g bullet traveling at a speed of 300 m/s enters a tree and exits the other side with a speed of 150 m/s. Where did the bullet’s lost kinetic energy go, and how much energy was transferred?