Physics question about momentum and Force, please help! (1 Viewer)

[Chris100]

A 1500 kg car is moving at 16 ms-1 when a net force of 300 N acts to slow the car. This force acts while the car moves through a distance of 120 m. The new speed of the car is:

(A) 19.5 ms-1
(B) 17.4 ms-1
(C) 14.0 ms-1
(D) 11.0 ms-1

 

[anomalousdecay]

momentum of car = (1500kg)(16 m s-1) = 24000kgm s-1

v=16m s-1 r= 120m

t= r/v = 7.5 s

momentum applied = (7.5 s)(-300 kgm s-2) = -2250 kgm s-1

Final momentum equal = (24000 - 2250) kgm s-1 = 21750 kgm s-1

final velocity = p/m = (21750 kgm s-1) / 1500kg = 14.5 m s-1

This should be in the preliminary section.
Next time post it there.

 

[gluecompass]

Sick question Chris...I wonder where u got that question from mate..cough cough