Because of your interest in the environment and your physics experience, you are
ID: 1442705 • Letter: B
Question
Because of your interest in the environment and your physics experience, you are assisting the Campus Museum of Natural History in the production of an animated film about hawks. In the script, a m1=1.5 kg hawk hovers motionless with respect to the ground when it sees a goose flying below it. The hawk dives straight down, striking the goose at a speed of v1=60 km/hr and digging its claws into the goose's body. The m2=2.5 kg goose was flying north horizontally at v2=30 km/hr just before it was struck by the hawk and killed. The animators want to know the velocity of the birds just after the strike.
Explanation / Answer
let north be +x direction and down be +y direction
m1 = 1.5 Kg
v1 = 60 y km/hr
m2 = 2.5 Kg
v2 = 30 x km/hr
use conservation of moomentum
m1*v1 + m2*v2 = (m1+m2)*v
1.5*60y + 2.5*30x = (1.5+2.5)*v
v = 22.5 y + 18.75 x
magnitude= sqrt (22.5^2 + 18.75^2 )
= 29.3 m/s
direction :
angle below north = atan (18.75/22.5)
= 39.8 degree