Question

Consider a father pushing a child on a playground merry-go-round. The system has a moment of...

Consider a father pushing a child on a playground merry-go-round. The system has a moment of inertia of 84.4 kg · m2. The father exerts a force on the merry-go-round perpendicular to its 1.50 m radius to achieve a torque of 375 N · m.

(a)

Calculate the rotational kinetic energy (in J) in the merry-go-round plus child when they have an angular velocity of 23.2 rpm.

(b)

Using energy considerations, find the number of revolutions the father will have to push to achieve this angular velocity starting from rest.

(c)

Again, using energy considerations, calculate the force (in N) the father must exert to stop the merry-go-round in four revolutions.

Science   Physics   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A playground merry-go-round of radius ? = 2.0 m has a moment of inertia ? =...
A playground merry-go-round of radius ? = 2.0 m has a moment of inertia ? = 250 kg ⋅ m^2 is rotating at 15 rpm about a frictionless, vertical axle. Facing the axle, a 25-kg child hops onto the merry-goround and manages to sit down on the edge. (a) (10 pts) What is the total angular momentum of the ‘merry-go-round-child’ system before and after the child hops on the the merry-go-round? (b) (10 pts) What is the new angular speed,...
A playground merry-go-round has a radius R and a rotational inertia I. When the merry-go-round is...
A playground merry-go-round has a radius R and a rotational inertia I. When the merry-go-round is at rest, a child with mass m runs with speed v along a line tangent to the rim and jumps on. The angular velocity of the merry-go-round is then
A 40 kg child (point mass) rides on the outer edge of a merry-go-round, which is...
A 40 kg child (point mass) rides on the outer edge of a merry-go-round, which is a large disk of mass 150 kg and radius 1.5 m. The merry-go-round spins with an angular velocity of 12 rpm. What is the merry-go-round’s angular velocity in radians per second (rad/s)? What is the total rotational inertia (moment of inertia) of the child and merry-go-round together? What is the rotational kinetic energy (in joules) of the merry-go-round and child together? What magnitude of...
A 23.0-kg child is riding a playground merry-go-round that is rotating at 30.0 rpm. (a)What centripetal...
A 23.0-kg child is riding a playground merry-go-round that is rotating at 30.0 rpm. (a)What centripetal force must she exert to stay on if she is 1.00 m from its centre? (b) What centripetal force does she need to stay on an amusement park merry-go-round that rotates at 3.00 rpm if she is 8.30 m from its centre? N (c) Compare each force with her weight. force from part (a) weight = force from part (b) weight =
A playground merry-go-round has a radius of 1.5 m and mass of 200 kg, and turns...
A playground merry-go-round has a radius of 1.5 m and mass of 200 kg, and turns with negligible friction about a vertical axle through its center. A child applies a constant force that produces a torque of 50 N·m to the merry-go-round. Its moment of inertia is given by I = ½MR2. The next four questions have to do with this rotating merry-go-round. Determine the angular acceleration of the merry-go-round in rad/s2. a. 0.047 rad/s2 b. 0.222 rad/s2 c. 0.965...
A child of mass 60 kg sits at the center of a playground merry-go-round which is...
A child of mass 60 kg sits at the center of a playground merry-go-round which is spinning at 1.5 rad/s. The moment of inertia and radius of the merry-go-round are 150 kg×m2 and 1.2 m respectively. How much rotational kinetic energy does the system lose as the child moves to the edge of the merry-go-round? (Treat the child as a point mass.)
A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with...
A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)=γt+βt3θ, where γ= 0.350 rad/s and β= 1.25×10−2 rad/s3. Calculate the angular velocity of the merry-go-round as a function of time. Express your answer in terms of the variables β, γ, and t. What is the initial value of the angular velocity? Calculate the instantaneous value of the angular velocity ωz at t= 4.90 s Calculate the average angular velocity ωav−z...
A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with...
A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)=γt+β t 3 , where γ= 0.378 rad/s and β= 1.10×10−2 rad/ s 3 . Part A Calculate the angular velocity of the merry-go-round as a function of time. Express your answer in terms of the variables β , γ , and t . Part B What is the initial value of the angular velocity? Part C Calculate the instantaneous value...
A playground merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg-m^2....
A playground merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg-m^2. When the merry-go-round is at rest, a 20-kg child runs at 5.0 m/s along a line tangent to the rim and jumps on. The angular velocity of the merry-go-round is then: .45 rad/s 1.2 rad/s .38 rad/s .56 rad/s .71 rad/s
A playground merry-go-round has a moment of inertia of 600 kg m2. When the merry-go-round is...
A playground merry-go-round has a moment of inertia of 600 kg m2. When the merry-go-round is at rest, a 20 kg boy runs at 5.9 m/s along a line tangential to the rim and jumps on, landing on the rim a distance of 3.0 m from the rotation axis of the merry-go-round. The angular velocity of the merry-go-round is then: A.1.2 rad/s B.0.38 rad/s C.0.45 rad/s D.0.56 rad/s E.0.72 rad/s
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT