Physics Problem: Kinetic Energy?
Could someone please help me with the answer to this problem? Thank you!!
The model airplane in figure below is flying at a speed of 24 m/s on a horizontal circle of radius 19 m. The mass of the plane is 0.97 kg. The person holding the guideline pulls it in until the radius becomes 13 m. The plane speeds up, and the tension in the guideline becomes four times greater. What is the net work done on the plane?
More Questions From This User See All
Answers & Comments
Verified answer
Net work done on the airplane = change (gain) in KE
Finding the final KE
F = mv²/R
v² = FR/m .. .. v² depends on F x R (m constant) ..
v² changes by a factor .. 4(for F) x 13/19(for R) = 2.74
Final vel ² = 2.74 x initial vel² .. .. 2.74 x 24² = 1578.24 .. .. (Vf)² = 1578.24
WD = ∆KE = ½ m (Vf ² - 24²) .. ½ x 0.97 (1578.24 - 24²) .. .. ►WD = 486.0 J