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A runner covers the last straight stretch of a race in 4 s. During that time, he speeds up from 5 m/s to 9 m/s. What is the runner’s acceleration in this part of the race?

User Roger Cornejo
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1 Answer

17 votes
17 votes

Given,

Time taken to cover the last last straight stretch of a race = 4 seconds

He speeds up from 5 m/s to 9 m/s

To find,

The acceleration of the runner.

Solution,

We can simply solve this numerical problem by using the following process.

Here,

Initial velocity (u) = 5 m/s

Final velocity (v) = 9 m/s

Time (t) = 4 seconds

Acceleration (a) = ?

According to the formula of kinematics,

a = (v-u)/t

a = (9-5)/4 [By putting the given values.]

a = 4/4 = 1 m/s²

(We have used SI unit of the acceleration, because all the initial physical quantities are also in SI units.)

Hence, the acceleration is 1 m/s²

User AnotherOne
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