5. Which description accurately describes the relationship between speed of fall and mass? Mass (g) Speed of Fall (m/s)
20 12
25 12
30 12
35 12
40 12
a. There is no relationship between the speed
of fall and mass

b. The speed of fall is proportional to the
square of the mass

c. The speed of fall is inversely proportional to
the mass

d. The speed of fall is directly proportional to
the mass

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied