Question

th a speed of 49 meters/second in the opposite direction. What is the impulse?A baseball with a mass of 0.145 kilograms collides with a bat at a velocity of 44 meters/second. The ball bounces off the bat with a speed of 49 meters/second in the opposite direction. What is the impulse?
4.32 newton∙seconds
7.25 newton∙seconds
8.23 newton∙seconds
9.42 newton∙seconds
13.5 newton∙seconds

Answer 1

Impulse, Δp, is the value of the change of the ball's momentum. To recall, we can express momentum, p, as the product of the object's mass and velocity. Mathematically, we have

$p = mv$
$\Delta p = m\Delta v$
$\Delta p = m(v_{final}-v_{initial})$

where m is the object's mass and v is the object's velocity.

Since the ball bounced off opposite to its original direction, initial velocity and final velocity will have opposite signs. And hence, we have

$\Delta p = 0.145(49 - -44) = 0.145(93) = 13.485$

Rounding the values off to three significant figures, we have Δp = 13.5 N·s.

Answer: 13.5 N·s