Answer:
4.5sec
Explanation:
From the question above, the following are the parameters that are given
u= 30m/s
v= 50m/s
s= 180m
First of all we have to find the acceleration by using the third equation of motion
V^2= U^2 + 2as
50^2= 30^2 + 2(a)(180)
2500= 900 + 360a
Collect the like terms
2500-900= 360a
1600=360a
Divide both sides by the coefficient of a which is 360
1600/360=360a/360
a= 4.44m/s
The next step is to find the time. To do this we will have to use the first equation of motion
v= u + at
50= 30 + 4.44t
Collect the like terms
50-30= 4.44t
20= 4.44t
Divide both sides by the coefficient of t which is 4.44
20/4.44= 4.44t/4.44
t= 4.5sec
Hence 4.5secs elapses while the auto moves at a distance of 180m
