Newton's second law for rotation Quiz 1

Question 1

Raman and Aman are two brothers and they see one body whose mass is 500 kg. If Raman apply a force of $$	ext{2}\sqrt{2 }	ext{ N}$$ and Aman apply a force of $$	ext{3}\sqrt{2}	ext{ N}$$ at the same time on a body at an angle to $$	ext{6}{{	ext{0}}^{\circ }}$$ to each other, then what will be the velocity of that body after 20 sec.

Accepted Answer

0.24 m/s

Answer

2.4 m/s

Answer

0.12 m/s

Answer

1.2 m/s

Question 2

Himanshu and Ravi pass the coin to each other in that way so that the coin moves in a circular way like a wheel of a car. If the time taken to reach the coin to Ravi from Himanshu is 40sec and in that time period the angular acceleration acting on that coin is $$85 	ext{rad/}{{	ext{s}}^{	ext{2}}}$$ then calculate the distance in radian so that the coin reached to Ravi. $$	ext{(Assuming that the torque acting on the coin is constant in every time when they pass to each other)}$$

Accepted Answer

68000 radian

Answer

76000 radian

Answer

69000 radian

Answer

71000 radian

Question 3

In a building whose height is 0.8 m, there are two people and one of them has a ball in his hand. If the first man is at top of the building and he has a ball in his hand and the other one man is at 0.2m from the ground and first man throws the ball and after rebound the second man catched that ball, and the time at which ball is contact with the ground is only 0.2 sec then find the Impulse. Assume that the mass of the ball is 80g. $$	ext{(Take g=10m/}{{	ext{s}}^{2}})$$

Accepted Answer

0.48Ns

Answer

0.56Ns

Answer

0.45Ns

Answer

0.39Ns

Question 4

A customer came in the rope shop, where he told to the shopkeeper that he wants a very thick rope so that the rope can easily support the lift which is present in his building and the weight of the lift is 4500Kg and he told that the maximum upward acceleration of the lift is $$	ext{2 m/}{{	ext{s}}^{	ext{2}}}$$and he also told that the rope must have breaking stress of $$5.4 	imes {10^{8}} N{{	ext{m}}^{	ext{-2}}}$$ so that it can easily support the lift. Now help the shopkeeper to find the rope by calculating the diameter of the rope.$$	ext{(Take g=10m/}{{	ext{s}}^{2}})$$

Accepted Answer

$$ 1.12	imes {{10}^{-2}}m$$

Answer

$$ 1.20	imes {{10}^{-2}}m$$

Answer

$$ 1.2	imes {{10}^{2}}m$$

Answer

$$ 1.02	imes {{10}^{-2}}m$$

Question 5

Ashu rides a roller coaster ride in the circus. When he sits on the seat of the ride after some time the ride starts and it moves in a fixed circular path. To check the velocity of the ride Ashu invented a device which measures the velocity and when he checks the velocity, he finds that the ride moves with a velocity of $$	ext{23} 	ext{m/s}$$. If the mass of the ride is 500g then what will be the angular momentum of the ride. $$	ext{(Assume that the perpendicular distance from the axis of rotation of the ride is 20m)}$$

Accepted Answer

$$230 	ext{kg}{{	ext{m}}^{	ext{2}}}	ext{/s}$$

Answer

$$340 kg{{	ext{m}}^{	ext{2}}}	ext{/s}$$

Answer

$$420 kg{{	ext{m}}^{	ext{2}}}	ext{/s}$$

Answer

$$190 kg{{	ext{m}}^{	ext{2}}}	ext{/s}$$