Two bodies A and B have masses 20 kg and 5 kg respectively. Each one is acted upon by a force of 4 kg-wt . If they acquire the same kinetic energy in times tA and tB, then the ratio (tA/tB) is

Question

Two bodies A and B have masses 20 kg and 5 kg respectively. Each one is acted upon by a force of 4 kg-wt . If they acquire the same kinetic energy in times tA and tB, then the ratio (tA/tB) is (A)  (1/2)  (B)  2  (C)  (2/5)  (D)  (5/6)

Tardigrade Admin · Accepted Answer

Here, m1=20 kg , m2=5 kg, Force =40 N ∴ a1=2 ms -2 and a2=8 m s -2 (1/2) m1(a1 tA)2=(1/2) m2(a2 tB)2 ∴ 20 × 4 × tA2=5 × 64 × tB2 ∴ (tA2/tB2)=(5 × 64/20 × 4)=(4/1) or (tA/tB)=2

Q. Two bodies $A$ and $B$ have masses $20 k g$ and $5 k g$ respectively. Each one is acted upon by a force of $4 k g - wt$ . If they acquire the same kinetic energy in times $t_{A}$ and $t_{B},$ then the ratio $\frac{t _{A}}{t _{B}}$ is

$\frac{1}{2}$

$2$

$\frac{2}{5}$

$\frac{5}{6}$

$\frac{1}{5}$

Q. Two bodies A and B have masses 20kg and 5kg respectively. Each one is acted upon by a force of 4kg−wt . If they acquire the same kinetic energy in times tA​ and tB​, then the ratio tB​tA​​ is

21​

2

52​

65​

51​

Here, m1​=20kg,m2​=5kg, Force =40N ∴a1​=2ms−2 and a2​=8ms−2 21​m1​(a1​tA​)2=21​m2​(a2​tB​)2 ∴20×4×tA2​=5×64×tB2​ ∴tB2​tA2​​=20×45×64​=14​ or tB​tA​​=2

Q. Two bodies $A$ and $B$ have masses $20 k g$ and $5 k g$ respectively. Each one is acted upon by a force of $4 k g - wt$ . If they acquire the same kinetic energy in times $t_{A}$ and $t_{B},$ then the ratio $\frac{t _{A}}{t _{B}}$ is

$\frac{1}{2}$

$2$

$\frac{2}{5}$

$\frac{5}{6}$

$\frac{1}{5}$