Question

Which has more kenetic energy: A 150 g bullet fired from a gun achieving a velocity of 440 m/s and a standard baseball weighing 51/4 oz being pitched at he MLB record speed of 105.1 mph. Calculate kinetic energy in Joules.

Answer 1

Bullet has more kinetic energy then baseball.

Step-by-step explanation:

Mass of the bullet , m = 150 g = 0.150 kg

Velocity of the bullet = v = 440 m/s

Kinetic energy =
`(1)/(2)* mass* (velocity)^2`

Kinetic energy of the bullet = K.E

`K.E=(1)/(2)mv^2=(1)/(2)* 0.150 kg* (440 m/s)^2`

`=14,520 Joules`

Mass of the baseball, m' =
`(51)/(4) oz`= 0.36146 kg

(1 ounce = 0.0283495 kg)

Velocity of the baseball= v' = 105.1 mph

1 mile = 1609.34 m

1 hour = 3600 seconds

`v'=( 105.1* 1609.34 m)/(3600 s)=46.98 m/s`

Kinetic energy of the baseball = K.E'

`K.E'=(1)/(2)m'v'^2=(1)/(2)* 0.36146 kg* (46.98 m/s)^2`

`=398.83 Joules`

14,520 Joules > 398.83 Joules

K.E > K.E'

Bullet has more kinetic energy then baseball.