A 92.45 kg baseball player slides to a stop at third base. The coefficient of kinetic friction between the player and the ground is 0.68. Her speed at the start of the slide is 6.87 m/s.
(a) Calculate her acceleration during the slide.
(b) How long (in time) does she slide until she stops?

a) Her acceleration during the slide is -6.67 m/s².

b) She slides 1.03 seconds until she stops.

a) We can find her acceleration during the slide with Newton's second law:

Where:

F: is the force    

m: is the mass = 92.45 kg

a: is the acceleration =?

The force acting on the baseball player is equal to the friction force (), and it is negative because it is in the opposite direction to the motion:

Where:

N: is the normal force = mg

μ: is the coefficient of kinetic firction = 0.68

g: is the acceleration due to gravity = 9.81 m/s²

Hence, her acceleration during the slide is:

b) We can calculate how long does she slide until she stops with the following kinematic equation:

Where:

: is the final speed = 0 (when she stops)

: is the initial speed = 6.87 m/s

t: is the time =?

Then, the time is:

You can learn more about Newton's second law here:

I hope it helps you!

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