Suzie (of mass 62 kg) is roller-blading down
the sidewalk going 16 miles per hour. She
notices a group of workers down the walkway
who have unexpectedly blocked her path, and
she makes a quick stop in 0.5 seconds.
What is Suzie’s average acceleration?
Answer in units of m/s^2
What force was exerted to stop Suzie?
Answer in units of N.
18 miles / hr * 0.44704 = 7.15 meters / second
acceleration = change in velocity / time = -7.15 / 0.5 = - 14.3 m/s^2 (more than g !)
F = m a = -62 *14.3 Newtons