A body covers 12 m in 3rd second of its linear uniformly accelerated motion. It covers 20 m in the 5th second. Velocity of the body after 10 s is

Question

A body covers 12 m in 3rd second of its linear uniformly accelerated motion. It covers 20 m in the 5th second. Velocity of the body after 10 s is (A) 40.25 ms-1 (B) 20 ms-1 (C) 42 ms-1 (D) 24 ms-1

Tardigrade Admin · Accepted Answer

Using, Sn = u+(1/2)a(2n-1), we get 12=u+(a/2)(2×3-1) =u+2.5 a ...(i) Also, 20=u+(a/2)(2×5-1) =u+4.5 a ...(ii) Solving (i) and (ii) a = 4ms-2 Using (i), we get 12 = u + (4/5)×5 i.e u=2ms-1 From the relation upsilon = u + at, we get, upsilon = 2 + 4 × 10 = 42 ms-1

Q. A body covers $12 m$ in $3 r d$ second of its linear uniformly accelerated motion. It covers $20 m$ in the $5 t h$ second. Velocity of the body after $10 s$ is

$40.25 m s^{- 1}$

$20 m s^{- 1}$

$42 m s^{- 1}$

$24 m s^{- 1}$

Q. A body covers 12m in 3rd second of its linear uniformly accelerated motion. It covers 20m in the 5th second. Velocity of the body after 10s is

40.25ms−1

20ms−1

42ms−1

24ms−1

Using, Sn​=u+21​a(2n−1), we get 12=u+2a​(2×3−1) =u+2.5a...(i) Also, 20=u+2a​(2×5−1) =u+4.5a...(ii) Solving (i) and (ii) a=4ms−2 Using (i), we get 12=u+54​×5 i.eu=2ms−1 From the relation υ=u+at, we get, υ=2+4×10=42ms−1

Q. A body covers $12 m$ in $3 r d$ second of its linear uniformly accelerated motion. It covers $20 m$ in the $5 t h$ second. Velocity of the body after $10 s$ is

$40.25 m s^{- 1}$

$20 m s^{- 1}$

$42 m s^{- 1}$

$24 m s^{- 1}$