Question

15. A catcher “gives” with the ball when he catches a 0.12 kg baseball moving at 17.4 m/s. If he moves his glove a distance of 3.86 cm, what is the average force acting on his hand? Answer in units of kN.

Answer 1

To determine the force, we need mass and acceleration.

In the given problem, only mass is given, so we need to determine the acceleration first.
the given quantities are
vi = 17.4 m/s
vf = 0
d = 0.0386 m
a = ?

we Use the kinematics equation that involves these quantities to solve for a:
a = (vf² - vi²)/(2d)
a = - vi²/(2d), since the final speed is 0

hence, a=-(17.4)²/(2*0.0386) = -3921.76 m/s²
Newton's Second Law states:
Force = Mass * Acceleration
F = ma
F = - m(vi)²/(2d) = 0.12*(-3921.76)  = - 470.6 N =-0.47 kN