Question

A speed skater just finished a race. After she crossed the finish line, she coasted to a complete stop. If her initial speed was 26.0 m/s and her acceleration was -3.8 m/s2, how long did it take her to stop?

A. 6.8 s
B. 3.4 s
C. 8.2 s
D. 9.6 s

Answer 1

The speed skater took approximately 6.8 seconds to stop.

Step-by-step explanation:

To find out how long it took for the speed skater to stop, we can use the equation:

final velocity = initial velocity + (acceleration * time)

Since the skater came to a complete stop, her final velocity is 0 m/s and her initial velocity is 26.0 m/s. The acceleration is -3.8 m/s². Plugging these values into the equation, we can solve for time:

0 = 26.0 + (-3.8 * time)

Rearranging the equation, we get:

26.0 = 3.8 * time

time = 26.0 / 3.8

time ≈ 6.84 s

Therefore, it took her approximately 6.8 seconds to stop.