PhysicsLAB: Momentum and Energy

Bronco Brown wants to put Ft = Δmv to the test and try bungee jumping. Bronco leaps from a high cliff and experiences free fall for 3 seconds. Then the bungee cord begins to stretch, reducing his speed to zero in 2 seconds. Fortunately, the cord stretches to maximum length just short of the ground below.

Refer to the following information for the next five questions.

In the table provided below, the first blank in each row is for Bronco Brown's instantaneous velocity at the time specified. The second blank is for his instantaneous momentum.

Use the magnitude of the acceleration of gravity (g) to be 10 m/sec². Express values in SI units: distance in m, velocity in m/sec, momentum in kg m/sec, impulse in N sec, and acceleration in m/sec². Bronco's mass is 100 kg.

0 sec

1 sec

2 sec

3 sec

5 sec

Refer to the following information for the next five questions.

Using the data from the chart above, complete these summary questions regarding Bronco's momentum, the impulse he received, and the average force he experienced.

The 3-second freefall distance of Bronco just before the bungee cord begins to stretch equals

Δmv during the 3-second interval of freefall equals

Δmv during the 2-second interval of slowing down equals

Impulse during the 2-second interval of slowing down equals

Average force exerted by the cord during the 2-second interval of slowing down equals

Refer to the following information for the next three questions.

Now, what about work and energy during his fall?

How much KE does Bronco have 3 seconds after his jump?

How much did his gravitational PE decrease during these 3 seconds?

What two kinds of PE are changing during the final two-second slowing-down interval?