Question

A car initially traveling with a velocity if 12 m/s accelerates at a constant rate of 2.5 m/s^2 for 2 seconds.

A) will this car cover more or less ground in 2 seconds than a second car initially moving at 12m/s but no acceleration ?

B) how far is this car moving after 2seconds ?

C) how far has it traveled during the 2 second interval ?

Answer 1

A) since the car is travelling with accleration at a constant rate. it will cover more ground than the second car which is moving without accleration.

B) we have from the kinematics,

v = u + a*t

where,

u = initial velocity = 12 m/s

a = accleration = 2.5 m/s²

t = time = 2 seconds

thus

v = 12 m/s + (2.5)(2) = 17 m/s

C) the distance can be calculated from the formula

s = u*t + at²/2
s = (12*2) + 0.5*(2.5)(2)² = 29 m
s = 22.5 m / 2 + 42 m
s = 11.25m + 42m
s = 53.25 m