Question

The initial velocity of a particle is 3 m/s east then it
becomes 4m/s west. The change in speed is
(a) 1 m/s
(b) 5 m/s
(c) 7 m/s
(d) 9 m/s​

Answer 1

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✴ The initial velocity of a particle is 3 m/s east then it becomes 4m/s west. The change in speed is

(a) 1 m/s

(b) 5 m/s

(c) 7 m/s

(d) 9 m/s

$\mathtt{\huge{\underline{\green{Answer:-}}}}$

➡ Option. B) 5 m/s

$\mathtt{\huge{\underline{\purple{Solution:-}}}}$

Given :-

• Initial velocity = v1 =3m/s east wards.
• time t=1 sec
• Towards east =3m/s
• v2 =4m/s north wards, Towards west =4m/s

To Find :-

The change in speed .

Calculation :-

VResultant = √v1²+v2²

=√3² + 4²

= √ 9 + 16

= √ 25

= 5m/s.

So, Velocity is 5m/s.

The change in speed is also known as acceleration a = v = velocity / time

= 5 × 1

= 5m/s toward east to west.

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Answer 2

✅ Given :-

• Initial Velocity = 3m/s

• Final Velocity = 4m/s

• Time = 1 second

✅ To Find :-

• Change occured in speed.

✅ Solution :-

We know that,

Resultant Formula :- $\sf{\sqrt{ {v}^{1} + {v}^{2} }}$

So, Put the values.

➛√3² + 4²

➛√25

➛5m/s.

Now,

Time Given :- 1 second.

5 × 1 = 5m/s

So, Your Answer Is 5m/s towards east to west.