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.

Respuesta :

Answer:

4.5s

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