Question

A woman of mass 50 kg is swimming with a velocity of 1.6 m/s. If she stops stroking and glides to a stop in the water, what is the impulse of the force that stops her?

Answer 1

Answer:

– 80 Ns.

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 50 kg

Initial velocity (u) = 1.6 m/s

Final velocity (v) = 0 m/s

Impulse (I) =?

Impulse is simply defined by the following equation:

I = Ft = m(v – u)

I = 50 (0 – 1.6)

I = 50 (–1.6)

I = – 80 Ns

Thus, the impulse of the force that stopped her is – 80 Ns.

NOTE: The negative sign indicates that the net force is in opposite direction to her movement.