A 68 kg person rides at a speed of 7.2 m/s on a bicycle that hasa mass of 8.1 kg. Each wheel is a hoop of radius 0.33 m and mass 1.4 kg (the mass of the wheels is included in the mass of the bicycle, and I= MR2for a hoop). (a)(2 points) At what angular speed are the wheels rotating? (b)(6 points) What is the total kinetic energy of the bicycle and rider? (c)(2 points) Assuming any friction is negligeable, if the cyclist coasts up a ramp (with an initial speed of 7.2 m/s), what vertical distance will the center of mass of the bicycle-rider system rise before the bike comes to rest?

(4ed) 10.1 The turntable of a record player rotates at a rate of 33 1/3 rev/min (rpm) and takes 60.0 s to come to rest when switched off.

Calculate (a) the magnitude of its angular acceleration

and (b) the number of revolutions it makes before coming to rest.

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft