Answer:
The total distance traveled by the car (S) = 15 mi
Explanation:
Total acceleration () = 10 mi /
Time (t) = 1 hour
Deceleration () = - 5 mi /
From law of speed we know that V = u + t -----------(1)
Where V = Final speed
u = initial speed and t = time period
Car starts from rest so initial speed is zero so u = 0
Then equation 1 becomes V = t = 10 × 1 = 10 mi / h ---------(2)
The distance traveled by the car = u t +
×
×
-------------(3)
Put all the values in equation we get = 0 +
× 10 ×
= 5 mi ---------------(4)
This is the distance traveled by the car in 1 hour.
In second case when car starts decelerates the equation of motion becomes
⇒ V = u - a t -----------(5)
final speed in this case = 0 and initial speed (u) = 10 mi / h
⇒ 0 = 10 - 5 t
⇒ 5 t = 10
⇒ t = 2 hours
Distance traveled by the car in to hours = u t +
×
×
⇒ = 10 × 2 -
× 5 ×
⇒ = 20 - 10
⇒ = 10 mi
This is the distance traveled by the car in the next two hours.
Thus the total distance traveled by the car = +
⇒ S = 5 + 10 = 15 mi