Please help! A pulley system is hanged in a lift as shown below in the
figure. A and B are two masses each having m and 2m mass
respectively. If d is the distance from the floor to B and the
lift starts to move with acceleration a, the time taken by B to reach the floor is,
1)
2)
3)
4)
5)

B

Explanation:

Find the acceleration of the system

m2>m1

further m2 = 2m

and m1 = m

The acceleration is going to be the downward force created by m2 divided by the total mass (m2 + m2)

a = (m2*g - m1*g) / (m1 + m2)

a = (2m - m)*g/ (2m + m)

a = m * g/3m

a = 1/3 * g

Formula for time

Givens

distance := d

acceleration : = a  

vi = 0

Kinematic Formula

d = vi * t + 1/2 a t^2

Solution

d = 0 + 1/2 * 1/3 g  * t^2

6d = g * t^2

t^2 = 6d/g

t = √(6d/g)

Answer.

B

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.