Question

2) A motorist travels with a constant speed of 30 m/s for 15s. He then accelerates at 3 m/s? for 8 s to reach his desired top speed. He drives at this top speed for 21s and then takes another 18 s to bring the car to a stop. Calculate the average speed for the entire period. 35.4 m/s 32.0m/s 37.1 m/s 33.7 m/s 38.3 m/s

Answer 1

2) Distance travelled with constant speed 30 m/s, d= 30x15 - 450 m Distance baretled with acceleration 3 m/32 d₂ = (30x8 + 13x82) m z (240 + 960m = 336 m speed at reaching the top speed, vo-J 30² + 2x3x336 ms. - 54 mis distance travelled due to travelling at this constant speed for 215 dz. 54821= 1134 m

come to stop in iss from de acceleration needed to velocity 54 m/s being a 0 = 54- ax 18 Or, az 3 m/s² Distance travelled with this acceleration, da = 548 18 – 1 x 3x 182 - 486 m so total distance travelled, d= dit dz7d3tda - 240 6 m in time, t= 625. ar speed = a = 38.80 m/s ~ Coption E) aver