Question

The linear speed of the tip of second arm of a clock is v. The magnitude of change in its velocity is 15 seconds is?
(A) zero
(B) v/â2
(C) â2 v
(D) 2 v

Answer 1

Dear Student,

◆ Answer - (C)

∆v = √2v

◆ Explanation -

Angular displacement in 15 s is given by -

θ = 2π × t/T

θ = 2π × 15/60

θ = π/2 rad

Change in velocity of second hand is given by -

∆v = 2v.sin(θ/2)

Substitute θ = π/2,

∆v = 2v.sin(π/4)

∆v = 2v × 1/√2

∆v = √2v

Therefore, magnitude of change in velocity of second hand in 15 seconds is √2v.

Thanks dear...

Answer 2

Answer:

◆ Answer - (C)

∆v = √2v

◆ Explanation -

Angular displacement in 15 s is given by -

θ = 2π × t/T

θ = 2π × 15/60

θ = π/2 rad

Change in velocity of second hand is given by -

∆v = 2v.sin(θ/2)

Substitute θ = π/2,

∆v = 2v.sin(π/4)

∆v = 2v × 1/√2

∆v = √2v

Therefore, magnitude of change in velocity of second hand in 15 seconds is √2v.

Explanation: