# An average force of 280 N acts for 1.2 seconds on a 78 kg circus performer as he is shot out of a cannon. (a) What impulse is applied to the performer? (b) What is the speed of the performer as he leaves the cannon?

Apr 5, 2018

I tried this:

#### Explanation:

The Impulse $I$ can be evaluated as:

$I = {F}_{a v} \Delta t = 280 \cdot 1.2 = 336 N s$

For the velocity we use the Theorem of Impulse and Change in Momentum consisdering the initial velocity of the performer as zero.

$I = \Delta p$

${F}_{a v} \Delta t = m {v}_{f} - m {v}_{i}$

$336 = \left(78 \cdot {v}_{f}\right) - \left(78 \cdot 0\right)$

rearranging:

${v}_{f} = \frac{336}{78} = 4.3 \frac{m}{s}$