Please can someone double-check my answers?

1) A ball with a mass of 0.15 kg has a velocity of 5m/s.It strikes a wall perpendicularly and bounces off straight backwith a velocity of 3 m/s. The ball underwent a change in momentumof?

1.20 kg*m/s

2) What braking force is supplied to a 3,000 kg cartraveling with a velocity of 35 m/s that is stopped in 12seconds?

F=8750 N

3) A 0.1 kg baseball is thrown with a velocity of 35m/s. The batter hits it straight back with a velocity of 60 m/s.What is the magnitude of the average impulse exerted on the ball bythe bat?

9.5 N*s

4) A 1 kg object is moving with a velocity of 6 m/s tothe right. It collides and sticks to a 2 kg object moving withvelocity of 3 m/s in the same direction. How much Kinetic energy islost in the collision?

3J

5) A 2 kg mass moving with a velocity of 7 m/s collideselastically with a 4 kg mass moving in the opposite direction at 4m/s. The 2 kg mass reverses direction after the collision and hasnew velocity of 3 m/s. What is the velocity of the 4 kgmass?

1 m/s

6) A mass of 3 kg is attached to a massless spring witha force constant 500 N/m. The mass rests on a horizontalfrictionless surface. The system is compressed a distance of 30 cmfrom the springs initial position and then released. The momentumof the mass when the spring passes its equilibrium positionis?

8660.25m/s

7) Can an object have energy without having momentum?Explain.

Yes an object can have energy without having momentum.For example, a rock that is at the top of a cliff has potentialenergy since it's not moving but there is no momentum.

8) Can an object have momentum without having energy?Explain.

No object that has momentum also has energy. This isbecause if the velocity is not then the kinetic energy is also not0 momentum is a vector, but energy is a scalar.

9) An object of mass 2 kg has a linear momentum of 6 kg.m /s. What is this objects Kinetic energy?

9J

10) A box with a mass of 2 kg accelerates in a straightline from 4 m/s to 8 m/s due to the application of a force whoseduration is 0.5 seconds. Find the average strength of thisforce?

16N

11) A 45 kg. girl is sitting on a seesaw 0.6 m from thebalance point. How far, on the other side, should a 60 kg. boy sitso that the seesaw will remain in balance?

0.45m

12) A solid cylinder consisting of an outer radius R1and an inner radius R2 is pivoted on a frictionless axle as shown.A string is wound around the outer radius and is pulled to theright with a force F1 = 3N. A second string is wound around theinner radius and is pulled down with a force F2 = 5N. If R1 = 0.75m and R2 = 0.35m, what is the net torque acting on thecylinder?

-0.5Nm

15) An object of mass 0.5 kg., moving in a circular pathof radius 0.25 m, experiences a centripetal acceleration ofconstant magnitude 9 m/s2 . What is the objects angularspeed?

6 rad/sec

16) An object, originally at rest begins spinning underuniform angular acceleration. In 10 seconds, it completes anangular displacement of 60 rad. What is the value of its angularacceleration?

1.2 rad/s^2

17) The moment of Inertia of a solid uniform sphere ofmass m and radius R is given by the equation I = (2/5) mR2 . Such asphere is released from rest at the top of an inclined plane ofheight h= 10 m, length L, and the incline angle Ω. If the sphererolls without slipping, find the linear speed at the bottom of theincline.

11.83m/s

18) An object spins with angular velocity 10 rad/s. Ifthe objects moment of Inertia increases by a factor of 2 withoutthe application of an external torque, what will be the object’snew angular velocity?

1/2 angular velocity (w)

19) A 0.05 kg ball is thrown upward from the ground withan initial velocity of 30 m/s. At its maximum height, the magnitudeof the balls acceleration is?

9.80 m/s^2

20) A 15 Newton force is applied to a mass M that isadjacent to a wall, as shown. If the mass is 2 kg, the force thatthe wall exerts on the mass is equal to?

15N