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A 2000 kg car starts from rest and coasts down from te top of 5m long driveway that is sloped at an angle of 20 degrees with the horizontal. If a constant 4000N frictional force resists the car's motion, find the speed of the car at the bottom of the driveway?

User Jasonmit
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1 Answer

3 votes

Answer:3.67 m/s

Step-by-step explanation:

Given

mass of car
m=2000 kg

Initial velocity
u=0

Length of track
L=5 m

inclination of driveway
\theta =20^(\circ)

Friction Force
F=4000 N

Sin component of weight accelerate the car while friction tries to oppose the car i.e.


mg\sin \theta -F=ma_(net)


a_(net)=g\sin \theta -(F)/(m)


a_(net)=9.8\sin 20-2=1.35 m/s^2

Using
v^2-u^2=2 as


v=final\ velocity


v=√(2* 1.35* 5)


v=√(13.517)=3.67 m/s

User JuanBonnett
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