A car moving at 20 m s⁻¹ overtakes a truck moving at 20 m s⁻¹. The car can accelerate at 0.5 m s⁻². Initially the vehicles are 40 m apart; the car is 3 m long and the truck 17 m long. The car returns to its lane only after its rear is 40 m ahead of the truck. Which statements are correct?
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Question

A car moving at 20 m s⁻¹ overtakes a truck moving at 20 m s⁻¹. The car can accelerate at 0.5 m s⁻². Initially the vehicles are 40 m apart; the car is 3 m long and the truck 17 m long. The car returns to its lane only after its rear is 40 m ahead of the truck. Which statements are correct?

Select all that apply

G1 Physics · Accepted Answer

Total relative displacement needed: 40 + 17 + 3 + 40 = 100 m. Initial relative speed = 20-20=0. Relative acceleration =0.5 m s⁻². 100 = 0 + (1/2)(0.5)t² t²=400 ⇒ t=20 s. Car distance: x = ut + (1/2)at² = 20(20)+(1/2)(0.5)(20²) = 500 m. Final speed: v = u+at =20+0.5(20) =30 m s⁻¹.