Q.14. An object of mass m, = 2 kg moving with an initial speed v = 6 m/s col- lides with a second object of mass m2 = 4 kg moving with an initial speed %3D v2 = 9 m/s as shown in the adjacent figure. The two masses continue their motion %3D as one body with a speed V, that makes an angle 0 with the x-axis. The x-component of the final velocity is V: a. V. = 5.881 m/s b. V. = 6.388 m/s c. V, = 8 m/s %3D 50 40 d. Vf. = 5.512 m/s m v-9 mis

1. A 2.50-kilogram mud ball drops from rest at a height of 13.0 m. If the impact between the ball and the ground lasts 0.51 s, what is the magnitude of the average force exerted by the ball on the ground? f60 f60 sst ssfo ssf60

A bat collides with a 0.300 kg baseball over a period of 2.00 ms (m = milli).  If v1=12.0 m/s, θ1=35° and v2=23 m/s, determine the magnitude of the force exerted on the ball by the bat.

30. An object of mass m, V 4.00 kg is tied to an object of mass m, 3.00 kg with String 1 of length l = 0.500 m. The combination is swung in a vertical circular String 1 e m2 String 2 path on a second string, String 2, of length € = 0.500 m. During the motion, the two strings are collinear at all times as shown in Figure P6.30. At the top of its motion, m, is traveling at v = 4.00 m/s. (a) What is the tension in String 1 at this instant? (b) What is the tension in String 2 at this instant? (c) Which string will break first if the combina- Figure P6.30 tion is rotated faster and faster?

5. The system starts at rest. mı = 2 kg m2 = 6 kg the angle is 20 degrees and µk=0.15. What is the velocity of the system after m2 moves a distance of 10 meters? uN m¡g

+ Algebraic manipulation. Two automobiles traveling at right angles to each other collide and stick together. Skid marks show the wreckage was traveling 21° from the original direction of car A. Find the original speed of car B in terms of car A's original speed (VA) if their masses are related by ßmд where ß =1.9. Fill in the missing factor below. MB UB VA Record your numerical answer below assuming three significant figures. Remember to include a "-" when necessary. HOLDe

The Moon is 60 Earth radii (i.e. 60 rEarth) from the center of the Earth and has a mass of 0.012 Earth masses (i.e. 0.012 mEarth) a. How many Earth radii is the center of mass (the “barycenter”) of the Earth-Moon system from the center of the Earth? b. Is the center of mass inside the Earth or outside the Earth? c. What point along the line from the center of the Earth to the center of the Moon orbits the barycenter of the Solar System in a (nearly) circular orbit (e.g. the center of the Earth, the barycenter of the Earth-Moon system, the midpoint, the center of the Moon)?

1. For the purposes of this problem make sure you remember that the positive x direction is to the right. A 0.500 kg crash cart was rolling to the left at &; = -1.00 m/s. It was hit with a rubber hammer. Just afterwards the cart was rolling to the right with Uf = +2.50 m/s. The hammer was in contact with the cart for only 5.00 milliseconds. Remember to specify the direction in your answers as either postive or negative. (a) What is the change in momentum, Ap, for the cart? (b) What is the Impulse, I, applied by the hammer to the cart? (c) What is the average force, F, applied by the hammer to the cart? +x X+ Vf +X

A stationary 2.17-kg object is struck by a stick. The object experiences a horizontal force given by F = at - bt 2, where t is the time in seconds from the instant the stick first contacts the object. If a = 1,500,000 N/s and b = 20,000,000 N/s?, what is the speed of the object just after it comes away from the stick at t = 2.55 x 103 s? %3D

3. An m = 55 kg sprinter, when starting a race, pushes back horizontally on the starting block with an average F = 590 N force for a time interval of t =0.68 second. a. What is the speed, in m/s, of the sprinter at the end of the 0.68 s? b. What is the distance, in meters, the sprinter traveled during the 0.68 s time interval?