Question

A body starts from rest and travels with uniform acceleration of 2 m/s2 . If its velocity is v after making a displacement of 9 m, then v is

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Answer 1

To Find :-

• The value of v.

Solution :-

Given,

• Initial velocity (u) = 0 ms-¹
• Acceleration (a) = 2 ms-²
• Displacement (s) = 9 m

Applying newton's 2nd equation of motion,

s = ut + ¹/2 × at²

[ Put the values ]

⟶ 9 = 0 × t + ¹/2 × 2 × t²

⟶ 9 = 1 × t²

⟶ t² = 9/1

⟶ t² = 9

⟶ t = ±√9

⟶ t = -3 s OR t = 3 s

[ Note :- Ignoring negative term ]

⟶ t = 3 s

Applying newton's 1st equation of motion,

v = u + at

[ Put the values ]

⟶ v = 0 + 2 × 3

⟶ v = 0 + 6

⟶ v = 6 ms-¹

Therefore,

The value of v is 6 ms-¹.

Answer 2

Answer:

The velocity of the body is 6m/s

Explanation:

Given that,

A body starts from rest and travels with a uniform acceleration of

$a = 2ms {}^{ - 2}$

Also given the body covers a displacement of 9m.We are required to find its final velocity v after covering a displacement of 9m.For that we use the kinematic equations of motion given below.

$s = ut + \frac{1}{2} a {t}^{2}$u=0,s=9m and a=2 therefore,

$9 = 0.t + \frac{1}{2} (2) {t}^{2} \\ = > t = 3 \: sec$

After 3 seconds the velocity can be found as

$v = u + at \\ = > v = 0 + 2(3) \\ = 6 \: ms {}^{ - 1}$

Therefore,The velocity of the body after covering a displacement of 9m is 6m/s

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