A car is moving in a straight line in 18 km per hour it is stopped in 5 sec by applying brake find the speed of the car in meter per second
Answers
A car is moving in a straight line in 18 km/hr. and is stopped in 5 seconds by applying brakes.
Given that, Initial velocity (u) of the car is 18 km/hr and time (t) is 5 seconds.
And final velocity (v) is 0 m/s (brakes are applied).
We have to find the speed of the car in m/s.
Given initial velocity or speed with which car is moving is 18 km/hr.
Now, to convert km/hr into m/s. Multiply it by 5/18.
⇒ 18 × 5/18 = 5 m/s
Therefore, the speed of the car is 5 m/s.
Further, if it asked about the distance and acceleration of the car. Then,
Distance = Speed × Time
Given time is 5 seconds and speed from the above calculations is 5 m/s. So,
Distance = 5 × 5 = 25 m
Also given that, the final velocity of the car is 0 m/s (as brakes are applied).
Now,
v = u + at
0 = 5 + a(5)
-5 = a(5)
a = -1 m/s² (Negative sign shows the retardation)
Given:-
- A car is moving in a straight line with a speed of 18 km/h.
- It stopped in 5 s by applying brake.
To find:-
The speed in m/s.
Solution:-
Initial velocity(u) = 18 km/h
Final velocity(v) = 0 km/h
So, the speed of the car is 18 km/h.
Now, speed in m/s:
18*5/18
= 5 m/s
So, the speed of the car in m/s is 5 m/s.
Note:-
The velocity of the car decreases, so it is a deceleration.