Question

A force F1 acting on a free mass m at rest produces in it acceleration of 1m/s2. Another force F2 acting on the same mass at rest can produce in it a velocity of 10m/s after 5 s. The greatest acceleration of the mass m when both forces F1 and F2 acts together will be...
option:
i8m/s^2
ii4
iii5
iv6
v2
vi7
kindly help fast​

Answer 1

Answer: The greatest acceleration must be 3 ms^-2

Explanation: Here, according to the question ;

For the force F1 , let us consider a free mass (M) = b kg  

acceleration (a1)= 1ms^-2

Then , we have the formula from Newtons 2nd law of motion ; i.e. F=ma

So, F1  =  M *a1

         = b kg* 1ms^-2

           = b  N

Also, for the force F2 ,

M = b kg (Since second force is also applied for the same mass)

Initial velocity (u) = 0 m/s (Since at first the body is at rest )

Final velocity (v) = 10 m/s

Time (t) = 5 sec.

Then, by formula we can write

F2 = M* a2

    = M* [(v-u) /t]

    = b * [(10 - 0 ) / 5]

    = 2b N

Then, for the greatest acceleration we have to add both the forces i.e.(F1+F2) for the same mass . So,

Greatest acceleration be 'A' and the total force be (F) then,

F1 + F2 = b +2b

F = 3b

M * A = 3b

b * A = 3b

Therefore, A= 3 ms^-2      Ans.