Question

a car moving on a straight line path covers a distance of 2km due east in 20 s and 2km due north in 20 s . calculate the speed and velocity of the car .(mention the direction velocity )​

Answer 1

Answer:

Firstly, Car moves in east.

Distance covered = 2 km = 2000 m

Time taken = 20 s

Then, Car moves in north.

Distance covered = 2 km = 2000 m

Time taken = 20 s

Now, Total Speed = Total Distance/Total Time

⇒ Speed = 2000+2000/20+20

⇒ Speed = 4000/40

⇒ Speed = 100 m/s

Now, Velocity = Displacement/Time

Here, Displacement can be found by using Pythagoras theorem : (See the diagram)

⇒ H² = A² + B²

⇒ H² = 2² + 2²

⇒ H² = 4 + 4

⇒ H² = 8

⇒ H = √8

⇒ H = 2√2

So, displacement = 2000×1.41 = 2,820 m

And Time = 40 s

Hence, Velocity = 2,820/40 = 70.5 m/s

Hence, the speed of the car = 100 m/s and the velocity of the car = 70.5 m/s due south west direction.

Answer 2

Given :-

A car moving on a straight line path covers a distance of 2km due east in 20 s and 2km due north in 20 s .

To Find :-

Speed

Velocity

Solution :-

We know that

1 km = 1000 m

2 km = 2 × 1000 = 2000 m

Now

Total distance = 2000 + 2000

Total distance = 4000 m

Total time = 20 + 20

Total time = 40 sec

Now

Average speed = 4000/40

Average speed = 1000 m/s

Finding displacement by pythagoras theorem

H² = 2² + 2²

H² = 4 + 4

H² = 8

H = √8

H = 2√2

Now

D = 2√2 × 2000

D = 4000√2

Now

V = D/T

V = 4000√2/40

V = 70.5

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