Coefficient of Viscosity

Q.

The velocity of water in a river is 18 km h^-1 near the surface. If the river is 5 m deep, find the shearing stress between the horizontal layers of water. The coefficient of viscosity of water = 10^-2 poise.

1. 0.2 N

2. 0.02 N

3. 0.002 N

4. 2N

Q.

A box starts drowning in the water such that it can touch the 50 m deep seabed with a velocity of 5 m/s. But just 3 seconds after the box began dipping, a swimmer too dives in the water. At what time he will be able to catch the box if he is going down with a constant velocity of 2 m/s?

1. 6 second
2. 5 second

3. 4 second

4. 8 second

Q. Explain graphs for a particle thrown vertically upwards with velocity v°.

Q. A block of mass m is released from top of smooth inclined wedge. Contact force by wedge on block along horizontal direction is maximum if

m द्रव्यमान के एक गुटके को चिकने आनत नत तल के शिखर से छोड़ा जाता है। क्षैतिज दिशा के अनुदिश गुटके पर नत तल द्वारा संपर्क बल अधिकतम होता है, यदि

1. θ = 60º
   
2. θ = 90º
   
3. θ = 45º
   
4. θ = 30º
   

Q. A liquid flowing with speed v through a horizontal pipe of cross sectional area A enters into another pipe of double the area of cross section. Now, the speed of the liquid is :

1. $v$
2. $2v$
3. $v/2$
4. $v/4$

Q. How many pascals is approximately 1 atm?

1. 10, 00, 000
2. 1, 00, 000
3. 1, 000
4. 10, 000