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?

– 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.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.