A robot runs forward with 5 ms for 10 s and immediately backwards with 5 m s-1 for 5 s. Which of the following statements is wrong?

Options

A. The average speed of the robot is `5 m s^(-1)`
B. The distance covered by the robot is more than its displacement.
C. The average velocity of the robot is `5 ms^(-1)`
D. The robot is moving at uniform speed.

Answer

B

Explanation

Given that :
Forward direction :
`V=5 ms^(-1)`
`T_(1)=10 s`
`rArr s_(1)=uxxt_(1)=5xx10=50 m`
Backward direction :
`v=5 ms^(-1)`
`T_(2)=5s`
`rArr s_(2)=v xxt_(2)=5xx5=25m`
Average speed `v_(avg)=("Total distance")/("Total time taken")`
`=(s_(1)+s_(2))/(t_(1)+t_(2))=(50+25)/(10+5)=(75)/(15s)`
`=5 ms^(-1)`
Average velocity, `v_(avg)=("Total displacement")/("Total time taken")`
`=(50-25)/(10+5)=(25)/(15)=(5)/(3)`
Hence the corret option is (c).