Q: A sport car accelerate at the rate of 2.80m/s². How long does it take to reach its top speed of 60.0 km/h, starting from rest ?
Answer:
5.95 s.
Step-by-step explanation:
From Newton's equation of motion,
a = (v-u)/t ................ Equation 1
Where a = acceleration of the car, v = final velocity of the car, u = initial velocity of the car, t = time taken to reach the top speed.
Making t the subject of the equation,
t = (v-u)/a.............. Equation 2
Given: a = 2.8 m/s², u = 0 m/s ( from rest), v = 60 km/h = (60×1000)/3600
v = 16.67 m/s.
Substitute into equation 2
t = (16.67-0)/2.8
t = 5.95 s.
Hence the time taken to reach the top speed = 5.95 s.