All buses and cars these days are fitted with a speedometer, which shows the velocity of the vehicle. A device called odometer records the distance moved by the vehicle. If the reading on the odometer of a vehicle in the beginning of a trip and after $40$ minutes were $1048\, km$ and $1096\, km$ respectively, calculate its average velocity. Will the reading on the speedometer show this velocity when the vehicle is moving ? Support your answer with reason.
All buses and cars these days are fitted with a speedometer, which shows the velocity of the vehicle. A device called odometer records the distance moved by the vehicle. If the reading on the odometer of a vehicle in the beginning of a trip and after $40$ minutes were $1048\, km$ and $1096\, km$ respectively, calculate its average velocity. Will the reading on the speedometer show this velocity when the vehicle is moving ? Support your answer with reason.
Average speed is given by
$V _{a v}=\frac{\text { Distance travelled }}{\text { Time taken }}$
The automobile travels a distance of $1096-1048$
$=48 km =48000 m$ in a time $40 min =2400 s$
Therefore, $V _{a v}=\frac{\text { Distance travelled }}{\text { Time taken }}=\frac{48000}{2400}$
$=20\, m s ^{-1}$
The speedometer measures the instantaneous speed and not the average speed, therefore, it will not show this speed.
Similar Questions
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.
Distinguish between terms speed and velocity.
Distinguish between terms speed and velocity.
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.
Draw a diagram to show the motion of a body whose speed remains constant but velocity continuously changes.
Draw a diagram to show the motion of a body whose speed remains constant but velocity continuously changes.
Can a particle be accelerated
$(i)$ if its speed is constant ?
$(ii)$ if its velocity is constant ?
Can a particle be accelerated
$(i)$ if its speed is constant ?
$(ii)$ if its velocity is constant ?