When you blink your eye, the upper lid goes from rest with your eye open to completely covering your eye in a time of 0.024 s.

a. estimate the distance that the top lid of your eye moves during a blink.

b. what is the acceleration of your eyelid? assume it to be constant.

c. what is your upper eyelid's final speed as it hits the bottom eyelid?

m = mass of pellet = 2.10 x 10⁻² kg

x = compression of spring at the time launch = 9.10 x 10⁻² m

h = height gained by the pellet above the initial position = 6.10 m

k = spring constant

using conservation of energy

spring potential energy = gravitational potential energy of pellet

(0.5) k x² = m g h

inserting the values

(0.5) k (9.10 x 10⁻²)² = (2.10 x 10⁻²) (9.8) (6.10)

k = 303.2 N/m