A 40kg girl is swinging on a swing from rest. Then, the power delivered when moving with a velocity of 2m/s upwards in a direction making an angle 60∘ with the vertical is
A
248√3W
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
392√3W
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
448W
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
580W
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is B392√3W Two force are acting on bob, tension and weight. Power of tension will be zero and that of weight is,
P = mgv cos(90∘+θ) P = mgv cos(90∘+60∘) =−mgv. sin60∘ =−40×9.8×2×√32=−392√3W ∴ Power delivered is 392√3W