Question

A car is merging onto a freeway (beginning at rest), accelerating at a constant rate of 10ft/sec2. How long does it take to reach merging speed at 70mph?

Answer 1

Answer:

10.3seconds

Step-by-step explanation:

Step one:

given data

acceleration,a= 10ft/sec^2

final velocity v= 70mph

first, let is convert mph to ft/sec

1mph is 1.46667 ft/sec

70 mph is x

cross multiply we have

x= 102.7ft/s

Step two:

we are using the first equation of motion

v=u+at

initial velocity u= 0m/s

102.7=0+10*t

102.7=10t

divide both sides by 10

t=10.3seconds