A particle has initial velocity 25 m s⁻¹ and constant acceleration -5 m s⁻². The total distance travelled in the first 8 s is:
Options

Question

A particle has initial velocity 25 m s⁻¹ and constant acceleration −5 m s⁻². The total distance travelled in the first 8 s is:

G1 Physics · Accepted Answer

The particle stops after 5 s. Distance before stopping = 25(5) − 2.5(25) = 62.5 m. In the next 3 s it reverses direction and travels distance = (1/2)(5)(3²) = 22.5 m. Total distance = 62.5 + 22.5 = 85 m.