Question

give me the answers for the qustions shown below

Answer 1

Answer:

25) b

26) a

Explanation:

see from the ground that the block is moving upward with the same acceleration as that of the lift .

We know that summation of all external forces acting on a body is equal to mass of the body multiplied by net acceleration of the body .

Here net force is ma as mass of body is m and acceleration is in the upward direction that is 'a'

Now if u draw the fbd of the block you can find that fcos(theta) = Nsin(theta) becoz no horizontal movement of the block has been observed.

so in horizontal direction fcos(theta) = Nsin(theta)

but in vertical direction you can see that

Ncos30 + fsin30 - mg = ma

here theta = 30