A car approaching a school zone slows down from $27 m / s$ to $9 m / s$ with constant acceleration $- 2 m / s^{2}$ . How much time is required to slow down to final velocity?

3 s

No worries! We‘ve got your back. Try BYJU‘S free classes today!

6 s

No worries! We‘ve got your back. Try BYJU‘S free classes today!

9 s

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

$12 s$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $9 s$
We know initial velocity $u = 27 m / s$ , final velocity $v = 9 m / s$ and acceleration $a = - 2 m / s^{2}$

As we kinow, $v = u + a t$
or, $v - u = a t$
or, $t = \frac{v - u}{a}$

Putting the values in above equation, we get,
$t = \frac{9 m / s - 27 m / s}{- 2 m s^{- 2}}$
or, $t = \frac{- 18 m / s}{- 2 m s^{- 2}}$
or, $t = 9 s$

Suggest Corrections

Similar questions

Q. A purple car is moving three times as fast as a yellow car. Each car slows down to a stop with the same constant acceleration. How much more distance is required for the purple car to stop ?

A toy car is powered by compressed air. When the car is fully pumped up and released, it accelerates at $2 m / s^{2}$ for 3 seconds. As soon as the air is exhausted the car begins to slow down. It travels a combined total of 27 meters before coming to rest. What is its rate of acceleration when stopping and what is the total time of the motion?

A toy car is powered by water and compressed air. When the car is fully pumped up and released, it accelerates at $2 \frac{m}{s^{2}}$ for 3 seconds. As soon as this water runs out the car begins to slow down. The car travels a combined total of 27 meters before coming to rest. What is its rate of acceleration when stopping and what is the total time of the motion?

Q. A fly wheel rotating at 420 r.p.m. slows down at a constant rate of

2 r a d / s^{2}

. What time is required to stop the fly wheel ? (in s)

Q. A truck covers

40.0 m

8 s

while smoothly slowing down to a final speed of

2 m / s

. Find its acceleration if it starts with a speed

10 m / s

Join BYJU'S Learning Program

A car approaching a school zone slows down from 27m/s to 9m/s with constant acceleration −2m/s2. How much time is required to slow down to final velocity?

The correct option is C 9sWe know initial velocity u=27m/s, final velocity v=9m/s and acceleration a=−2m/s2 As we kinow, v=u+at or, v−u=at or, t=v−ua Putting the values in above equation, we get, t=9m/s−27m/s−2ms−2 or, t=−18m/s−2ms−2 or, t=9s

A car approaching a school zone slows down from $27 m / s$ to $9 m / s$ with constant acceleration $- 2 m / s^{2}$ . How much time is required to slow down to final velocity?