Physics HW ?-Acceleration and Force

Question

In t-ball, young players use a bat to hit a stationary ball off a stand. The 140 g ball has about the same mass as a baseball, but it is larger and softer. In one hit, the ball leaves the bat at 12 m/s after being in contact with the bat for 2.0 ms. Assume a constant acceleration during the hit.

1. What is the acceleration of the ball?
2. What is the net force on the ball during the hit?

Answer 1

Viewing this as an impulse and momentum problem I started with

impulse = F × t = m × v = momentum

Then wrote

F = mv/t = (0.14 kg × 12 m/s)/(2 × 10^-3 s)

and

a = F/m = (12 m/s)/(2 × 10^-3 s)

which led me to the same place as the first answer posted. (In other words, just read the first answer—where everything is explained perfectly.)

Answer 2

1. To find the acceleration of the ball:

Acceleration (a) = Change in Velocity (v) / Time (t)

Given, final velocity (v) = 12 m/s (since the ball started from rest)

Time (t) = 2.0 ms = 0.002 seconds

Acceleration (a) = 12 m/s / 0.002 s = 6000 m/s^2

So, the acceleration of the ball is 6000 m/s^2.

2. To find the net force on the ball during the hit:

Force (F) = Mass (m) x Acceleration (a)

Given, mass (m) = 140g = 0.14 kg

Acceleration (a) = 6000 m/s^2

Force (F) = 0.14 kg x 6000 m/s^2 = 840 N

So, the net force on the ball during the hit is 840 N.