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Motion | Motion - Exercise

Question 31

A motorcyclist drives from A to B with a uniform speed of 30 km h–1 and returns back with a speed of 20 km h–1. Find its average speed.

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Let the distance from A to B is D kms.

Distance for the entire journey is 2D kms.

Time taken to go from A to B is D/30 hr and that of B to A is D/20 hr. So, total time taken T

T = (D/30) + (D/20). By solving, we will get,

T = D/12 hrs.

Average speed = Total distance/Total time.

Av.speed = 2D ÷ D/12

=> 2D x 12/D = 24 km/h.

Hence Average speed of the motocycle is 24 km/h.

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Question 31

A motorcyclist drives from A to B with a uniform speed of 30 km h–1 and returns back with a speed of 20 km h–1. Find its average speed.

Looking to do well in your science exam ? Learn from an expert tutor. Book a free class!

Let the distance from A to B is D kms.

Distance for the entire journey is 2D kms.

Time taken to go from A to B is D/30 hr and that of B to A is D/20 hr. So, total time taken T

T = (D/30) + (D/20). By solving, we will get,

T = D/12 hrs.

Average speed = Total distance/Total time.

Av.speed = 2D ÷ D/12

=> 2D x 12/D = 24 km/h.

Hence Average speed of the motocycle is 24 km/h.

Our top 5% students will be awarded a special scholarship to Lido.

subject-cta
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