Question

If a body is dropped freely under gravity, then its velocity after 4 second will be.​

Answer 1

Initial velocity of the body (u) = 0 m/s

Since dropped freely under gravity

Acceleration due to gravity (g) = 10 m/s²

Time (t) = 4 s

Velocity after 4 s (v) = ? m/s

Apply 1st equation of motion ,

→ v = u + at

→ v = u + gt

→ v = (0) + (10)(4)

→ v = 0 + 40

→ v = 40 m/s

Velocity of the body after 4 seconds is 40 m/s

More Info :

⊕ Equations of motion :

→ v = u + at

→ s = ut + ¹/₂ at²

→ v² - u² = 2as

→ Sₙ = u + ᵃ/₂ ( 2n - 1 )

Answer 2

➲GIVEN:-

•Intial velocity,(u) =0 m/s

•time(t)=4s

➲TO FIND OUT:-

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•Final velocity after 4 s (v)=?⠀⠀⠀

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➲ANSWER:-

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•Since the body is dropped freely under gravity

So,Acceleration due to gravity (a)=9.8m/s²

➣Now using 1st equation of motion ,we have

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➱v=u+at

➱v=0+4×9.8

➱v=39.2 m/s

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➣Or (Taking a=10 m/s²) we have,

➱v=0+4×10

➱v=40m/s

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NOTE-In question the exact value of acceleration due to gravity is not mentioned. So we solved by both the value of 'a' and both answers are correct.

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MORE INFORMATION WHEN OBJECT DROPPED IN FREELY UNDER GRAVITY.

• Final Velocity is calculated gravity × time.

• The distance the object falls, or height, h, is 1/2 gravity × the square of the time falling.