Which describes a stationary reference point?

a. a slower moving truck from the point of view of a car passing it

b. a tree from the point of view of someone in a moving car

c. a plane from the point of view of a falling skydiver

d. the sun from the point of view of someone sitting outside

i think that is C a plane frm the point of view of a falling skydiver:

Explanation:

56 moles of   lieter in chemistry

(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