A bus decreases its speed from $80\, km\, h^{-1}$ to $50 \,km h ^{-1}$ in $4\, s$. Find the acceleration of the bus.
A bus decreases its speed from $80\, km\, h^{-1}$ to $50 \,km h ^{-1}$ in $4\, s$. Find the acceleration of the bus.
Given $v=50 km h ^{-1}=50 \times \frac{5}{18}=\frac{125}{9} m s ^{-1}$
$u=80 km h ^{-1}=80 \times \frac{5}{18}=\frac{200}{9} m s ^{-1}$
$t=4 s$
Using the expression $v=u+a t,$ we have
$a=\frac{v-u}{t}=\frac{125-200}{9 \times 4}=-2.083 m s ^{-2}$
Similar Questions
$(a)$ Derive graphically the equation for velocity$-$time relation.
$(b)$ Name the device used to measure distance travelled by a vehicle.
$(c)$ Can displacement of a moving object be zero ? Give reason.
$(a)$ Derive graphically the equation for velocity$-$time relation.
$(b)$ Name the device used to measure distance travelled by a vehicle.
$(c)$ Can displacement of a moving object be zero ? Give reason.
A car is moving on a straight road with uniform acceleration. The following table gives the speed of the car at various instants of time.
Time $(s)$
$0$
$10$
$20$
$30$
$40$
$50$
Speed $\left(m s^{-1}\right)$
$5$
$10$
$15$
$20$
$25$
$30$
$(i)$ Draw the speed$-$time graph representing the above set of observations.
$(ii)$ Find the acceleration of the car.
A car is moving on a straight road with uniform acceleration. The following table gives the speed of the car at various instants of time.
| Time $(s)$ | $0$ | $10$ | $20$ | $30$ | $40$ | $50$ |
| Speed $\left(m s^{-1}\right)$ | $5$ | $10$ | $15$ | $20$ | $25$ | $30$ |
$(i)$ Draw the speed$-$time graph representing the above set of observations.
$(ii)$ Find the acceleration of the car.
Two cars moving in opposite directions cover same distance $'d'$ in one hour. If the cars were moving in north$-$south direction, what will be their displacement in one hour ?
Two cars moving in opposite directions cover same distance $'d'$ in one hour. If the cars were moving in north$-$south direction, what will be their displacement in one hour ?
Define velocity.
Define velocity.
What does the slope of velocity$-$time graph represent ?
What does the slope of velocity$-$time graph represent ?