Physics
posted by value .
A 600kg car is moving on a level road at 30m/s.how large is a retarding force is required to stop it in a distance of 70m

Physics 
Anonymous
speed:
v = 30 + a t
what is a when v = 0
30 = a t
a = 30/t
distance:
70 = 30 t + (1/2) a t^2
70 = 30 t (15/t) t^2
70 = 15 t
t = 14/3 seconds to stop
a = 30/t = 90/14 m/s^2 = 45/7
then F = m a
F = 600 (45/7) Newtons 
Physics 
bobpursley
There is a quicker way:
vf^2=vi^2+2ad but a= forcefriction/mass
0=30^2+2*force/mass * 70
solve for force.
Respond to this Question
Similar Questions

Physics
A 1100 kg car is moving toward the north along a straight road at a speed of 20.0 m/s. The driver applies the brakes and the car comes to rest in a distance of 140 m. (a) If the road is completely level, what is the constant force … 
Physics
A 1100 kg car is moving toward the north along a straight road at a speed of 20.0 m/s. The driver applies the brakes and the car comes to rest in a distance of 140 m. (a) If the road is completely level, what is the constant force … 
physics
A car traveling 72.0 km/h along a straight, level road is brought uniformly to a stop in a distance of 40.0 m. If the car weighs 8.8 x 103 N, what is the braking force? 
physics
A car traveling 72.0 km/h along a straight, level road is brought uniformly to a stop in a distance of 40.0 m. If the car weighs 8.8 x 103 N, what is the braking force? 
Physics
A car travels at 64 mi/h when the brakes are suddenly applied. Consider how the tires of a moving car come in contact with the road. When the car goes into a skid (with wheels locked up), the rubber of the tire is moving with respect … 
Physics
A car moving initially at a speed of 80 km/h and weighing 13,000 N is brought to a stop ina distance of 61 m. Find(a) the braking force and (b) the time required to stop. Assuming the same braking force, find (c) the distance and (d) … 
physics
A 600 kg car is moving on a level road at 30 m/s. How large of a braking force is needed to stop it in a distance of 75m? 
PHYSICS
A CAR IS MOVING INITIALLY AT A SPEED OF 50MI/H WEIGHTING 3000LB IS BROUGT TO A STOP IN A DISTANCE OF 200FT FIND THE BRAKING FORCE.AND FIND TIME REQUIRED TO STOP ASSUMING THE SAME BRAKING FORCE..AND FIND THE DISTANCE AND TIME REQUIRED … 
Physics
A car of mass 1000 kg moving with a velocity of 30m/s applies break and stop after 3s. Find the magnitude of retarding force, the distance travelled by the car before it came to rest and the work done by the breaking force. 
physics
A car has a mass of 1200 kg and is traveling perfectly horizontally on a road at 20 m/s. The car then applies the brakes and skids to a stop. If the coefficient of friction between the tires and road is .70, how much distance was required …