In: Physics
You push a small mass (with respect to your mass) crate on a frictionless surface and it has some acceleration. If you are standing on the same frictionless surface, what happens to you?
a) |
You stay where you are. |
|
b) |
You move forward at very low velocity. |
|
c) |
You move backward at very low velocity. |
|
d) |
You move forward at very high velocity. |
|
e) |
You move backward at very high velocity |
According to Newton's third law of motion, every action has its equal and opposite reaction. If I push a small mass crate on a frictionless surface and it has some acceleration, the equal amount of force ( magnitude of the force is equal to the force exerted by me on the small mass) is exerted by the small crate on me in the backward direction ( according to Newton's third law of motion). The total linear momentum of the system ( me and the crate) should be conserved ( according to Newton's second law of motion).
If M and m are the mass of my body and the crate respectively and V and v are the velocities of my body and the crate respectively,
M*V + m* v =0
V = (- m / M ) * v
If m < M, V < v which means that my velocity will be less than the crate's velocity.
The negative sign of V signifies that my motion will be in the backward direction.
So, option (c) is correct i.e. I move backward at very low velocity (Ans).