Mechanics, Question 1
A car moves in a straight line along a horizontal road with constant acceleration 2 m s–2 The car is moving with speed 15 m s–1 in the direction of the acceleration when it passes a signpost on the road. The car is modelled as a particle.
Use the model to find the speed of the car 4 s after passing the signpost. Figure 1 below shows the horizontal forces acting on the car. Given that
(2)
• the car has mass 800 kg
• the driving force of the engine has magnitude D newtons
• the resistance to the motion of the car has magnitude 400 N
• the acceleration of the car is 2 m s–2 in the direction of the driving force
use the model to find the value of D.
(2)