Question

IP In baseball, a pitcher can accelerate a 0.12-kg ball from rest to 91 mi/h in a distance of a 1.7 m What is the average force exerted on the ball during the pitch?

If the mass of the ball is increased, is the force required of the pitcher increased, decreased, or unchanged?

Explain.

Answer 1

(a) given data:

mass of the ball (m) = 0.12 kg;

distance (s) = 1.7 m;

intial velocity u = 0 m/s (at rest);

(b) if mas is increased then the force required of the pitcher increased;

as F = ma.

final velocity v = 91 mi/h;

converting engish units in meteric units as 1 mi/h = 1.609 km /mi;

therefore, final velocity v = (91 mi/h) x (1.609 km /mi)

= 146.419 km/h

= 146419 m/h

= 40.67 m/s;

final velocity v = 40.67 m/s;

now, use 3rd law of motion;

v² = u² + 2a*s;

40.67² = 0² + 2a*(1.7);

a = 486.53 m/s²;

now avarage force F = ma;

F = 0.12*486.53;

F = 58.38 N.