Question

a car moving on a road with a uniform acceleration covers 20m in the first second and 40m in next second what is the acceleration! please answer me with full explanation
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Answer 1

Answer:

distance travelled in 1st second=20m

time taken to travel this distance=1s

So speed in first second is dist/time = 20m/s

Similarly speed in 2nd second is 40m/s

Now acceleration = dv/dt

Here dv means change in v, where v is velocity and dt means change in t where t is time interval.

Change in velocity = final vel. — initial vel.

That is, 40-20 = 20m/s

And change in time = 2 — 1 = 1s

So acceleration is 20m/s / 1s = 20m/s^2 Ans.

Metre per second square is the standard unit of acceleration.

Explanation:

Answer 2

Answer:

Let the initial velocity be u and acceleration be a.

Case 1 :

Distance covered S=20 m

Time taken t=1 s

Using S=ut+

2

1

at

2

Or 20=u(1)+

2

1

a(1)

2

⟹ 20=u+

2

a

We get u=20−

2

a

Case 2 :

Total distance covered S=20+30=50 m

Total time taken t=1+1=2s

So, 50=u(2)+

2

1

a(2)

2

or 50=2u+2a

Or 50=2(20−

2

a

)+2a

Or 50=40−a+2a

⟹ a=10 m/s

2

Explanation:

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