Question
question 44
tom of the swing? (b) Explain why the tension is greater than the weight of the bob. t a car 42. A 35.0-kg child swings on a rope with a length of ithout 6.50 m that is hanging from a tree. At the bottom of the curve. swing, the child is moving at a speed of 4.20 m/s. What ded if is the tension in the rope? 43. A car approaches the top of a hill that is shaped like a vertical circle with a radius of 55.0 m. What is the fast- est speed that the car can go over the hill without losing contact with the ground? m/s 5.6 Angular Acceleration mass 44. A child pushes a merry-go-round from rest to a final angular speed of 0.50 revls with constant angular accel- of the eration. In doing so, the child pushes the me force round 2.0 revolutions. What is the angular acceleration meth- of the merry-go-round? that the wheels One, 45. A cyclist starts from rest and pedals so is the angu- 16 h. make 8.0 revolutions in the first 5.0 s. What long lar acceleration of the wheels (assumed constant)? lution 46. During normal operation, a computer's hard disk spins at 7200 rpm. If it takes the hard disk 4.0 s to reach this angular velocity starting from rest, what is the average
Explanation / Answer
44)
wf2=wi2+2*alpha*delta(theta)
alpha=angular accelration
alpha=0.52-0/2*2
=0.0625rev/s2
1rev=2*pi radians
=0.0625*2*3.14 rad/s2
=0.3925rad/s2
