a car runs with a negative acceleration of -0.5m/s^2. the initial velocity of the car is 54 km/hr. In how much time and how far from the initial point will the car stop?

1
by agrawal

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a car runs with a negative acceleration of -0.5m/s^2. the initial velocity of the car is 54 km/hr. In how much time and how far from the initial point will the car stop?

1
by agrawal

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acceleration (a)= - 0.5 m/s²

initial velocity (u) = 54 km/hr

As the acceleration is given in m/s² let us convert the initial velocity also into m/s²

therefore

initial velocity = 15 m/s

1)We have to find the time(t) taken by the car to get stopped

From v = u + at

the final velocity(v) = 0 . since the car is retar ding

0 = 15 + (- 0.5) t

0.5*t = 15

t = 30 seconds. This is time taken by the car to stop.

2)Now we find the displacement(s) covered by the car before it stops

From v² - u² = 2as

by substituting we get

0 - (15)² = 2(- 0.5)s

1*s = 225

s = 225 m . This the displacement covered by car before it stops .