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प्रश्न
A car acquire a velocity of 72 km per hour in 10 second starting from rest. Find
(1) the acceleration,
(2) the average velocity, and
(3) the distance travelled in this time.
उत्तर
We have the following information,
Initial velocity, (u) = 0 m/s
Final velocity
`(v)` = 72 km/hr
= `"72(1000)"/3600` m/s
= 20 m/s
Time taken , (t) = (10) s
(i) So acceleration,
`a = (v-u)/t`
Put the values in the above equation to get the value of acceleration
`a = (20-0)/10`
= 2 `"m/s"^2`
(ii) we have to find the average velocity. we will use the following relation,
Average velocity = `"Initial velocity + Final velocity"/2`
So , Average velocity = `(v+u)/2`
Therefore putting the value in the above to get the avearge velocity ,
Average velocity = `(20+0)/2` m/s
= 10 m/s
(iii) We have to calculate the distance travelled. We will use the relation,
Distance travelled = (Average velocity) (Time)
So distance travelled is,
= (10)(10) m
= 100 m
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