Question

A dragster travels 1/4 mi in 6.7 s. Assuming that acceleration is constant and the dragster is initially at rest, what is its velocity when it crosses the finish line?. . Please show me step by step

Answer 1

The given values are:
Vo = 0 m/s
x = 1.4 mi = 402.336 m
t = 6.7 s

The velocity of the dragster when it crosses the finish line is calculated as follows:

x=(at^2)/2
a=2x/t^2
a=2(402.336 m) / (6.7 s)^2
a=17.93 m/s^2

V=Vo+at
V=0+17.93 m/s^2 x 6.7s
V= 120.131 m/s

Answer 2

V0=0m/s (initially at rest)
t=6,7s
s=1/4mi=402,336m
s=(a*t^2)/2   ->   a=2*s/t^2    ->  a=2*402,336m/(6,7s)^2
a=804,672/44,89=17,93 m/s^2
v=v0+at
v=0+17,93 m/s^2 * 6,7s = 120,131 m/s = 432,4716 km/h