Question

guys please solve this quickly.......no spam please.... ​

Answer 1

Question :

A stone connected with a string is rotated in a vertical circle, speed of stone at bottom most point is √8gR, where R is the radius of circle. The ratio of tension in string at the top and the bottom is :-

Answer :

In order to find tension at highest point, we have to find velocity of stone at that point.

Let velocity of ball at lowest point be v and at highest point be v'$.$

★ At point A :

• Potential energy : 0

• Kinetic energy : 1/2 mv²

• 1/2 m (√8gR)²
• 1/2 m (8gR)
• 4mgR

• Mechanical energy = 4mgR

★ At point B :

• Potential energy : 2mgR

• Kinetic energy : 1/2 mv'²

• Mechanical energy = 2mgR + 1/2 mv'²

Let's apply concept of mechanical energy conservation.

➝ 4mgR = 2mgR + 1/2 mv'²

➝ 1/2 mv'² = 2mgR

➝ v' = √4gR

∴ Velocity of stone at highest point will be √4gR.

Tension in the string at point A :

➝ T₁ = mv²/R + mg

➝ T₁ = m(√8gR)²/R + mg

➝ T₁ = 8mg + mg

➝ T₁ = 9mg

Tension in the string at point B :

➝ T₂ = mv'²/R - mg

➝ T₂ = m(√4gR)²/R - mg

➝ T₂ = 4mg - mg

➝ T₂ = 3mg

Taking ratio of T₂ and T₁ ;

➠ T₂ / T₁ = 3mg / 9mg

➠ T₂ : T₁ = 1 : 3

∴ (2) is the correct answer!

Answer 2

Explanation:

2 answer is correct

hope my answer is satisfied you

plz follow me