Question

А)

An automobile traveling along a straight road
increases its speed from 48 ft/s to 66 ft/s in
180 ft.
If the acceleration is constant, how much
time elapses while the auto moves the 180 ft?
Answer in units of s.

Answer 1

4.5s

Step-by-step explanation:

u=30m/s

v=50m/s

s=180m

a=constant(given)

By third equation of motion, v

2

=u

2

+2as

(50)

2

=(30)

2

+2a(180)

a=

3

40

​

m/s

2

By first equation of motion, v=u+at

50=30+(

9

40

​

)t

t=

2

9

​

=4.5sec