Question

A skydiver slows down from 65 m/s to 5 m/s by opening the parachute. If this

Answer 1

Answer:

$\boxed {\boxed {\sf D. \ 80 \ m/s^2 \ down}}$

Explanation:

We are asked to find the acceleration of a skydiver. Acceleration is the change in velocity over the change in time, so the formula for calculating acceleration is:

$a= \frac{v_f-v_i}{t}$

The skydiver was initially traveling 65 meters per second, then he slowed down to a final velocity of 5 meters per second. He slowed down in 0.75 seconds.

$\bullet \ v_f = 5 \ m/s \\\bullet \ v_i= 65 \ m/s \\\bullet \ t= 0.75 \ s$

Substitute the values into the formula.

$a= \frac{ 5 \ m/s - 65 \ m/s}{0.75 \ s}$

Solve the numerator.

$a= \frac{-60 \ m/s}{0.75 \ s}$

Divide.

$a= -80 \ m/s^2$

The acceleration of the skydiver is -80 meters per second squared or 80 meters per second squared down. The skydiver is slowing down or decelerating, so the acceleration is negative or down.

Answer 2

Answer:

D. -80m/s^2

Explanation:

V = u + at

5 = 65 + a (0.75)

0.75a = -60

a = -60/0.75

a = -80m/s^2

Therefore, is decelerating at 80m/s^2