# Bouncing a Baby to Sleep#

Some babies like to be bounced to calm them down. A babyâs mother (96.9 kg) sits on a âbirthingâ ball and bounces a 7.95 kg baby with them with frequency 1.35 Hz, and finds that the baby goes to sleep. The babyâs father (67.8 kg) tries the same technique, but finds that the baby wonât go to sleep. They realize that this is because they canât bounce on the ball with the same frequency as the babyâs mother.

## Part 1#

Assuming this to be simple harmonic motion, what is the spring constant of the ball (assume that it remains unchanged by the added weight)?

Please enter in a numeric value in $$N/m$$.

## Part 2#

What adjustment to the spring constant needs to be made for the father to put his child to sleep?

Please enter in a numeric value in $$N/m$$.

## Part 3#

How could such an adjustment be made to the ball, which is filled with air?

• Remove air to decrease the pressure in the ball. Decreased pressure makes the ball âsofterâ.

• Remove air to decrease the pressure in the ball. Decreased pressure makes the ball âstifferâ.

• Remove air to increase the pressure in the ball. Increased pressure makes the ball âsofterâ.

• Remove air to increase the pressure in the ball. Increased pressure makes the ball âstifferâ.

• Add more air to decrease the pressure in the ball. Decreased pressure makes the ball âsofterâ.

• Add more air to decrease the pressure in the ball. Decreased pressure makes the ball âstifferâ.

• Add more air to increase the pressure in the ball. Increased pressure makes the ball âsofterâ.

• Add more air to increase the pressure in the ball. Increased pressure makes the ball âstifferâ.