Chapter 15, Problem 136P

3/183 The rocket engine of a 30-Mg spacecraft traveling at a speed of 24 000 km/h is fired and produces a thrust of 20 kN in the direction of its circular path for a period of 3 min. Determine the new speed of the spacecraft. The loss of mass due to fuel burned is negligibly small.

A baseball (m = 0.18 kg) has an initial velocity of v=-35 m/s as it approaches a bat. We have chosen the direction of approach as the negative direction. The bat applies an average force F that is much larger than the weight of the ball, and the ball departs from the bat with a final velocity of v=58 m/s.   Determine the impulse applied to the ball by the bat.

Each of the two stages A and B of the rocket has a mass of 2 M-g (M=mega) when their fuel tanks are empty. They each carry 300 kg of fuel and are capable of consuming it at a rate of 50 kg/s and eject it with a constant velocity of 2500 m/s, measured with respect to the rocket. The rocket is launched vertically from rest by first igniting stage B. Then stage A is ignited immediately after all the fuel in B is consumed and A has separated from B Neglect drag resistance and the variation of the rocket’s weight with altitude.   Given: Ma = Mb = 2000 Kg M Fuel = 300 Kg Fuel Consumption = 50 Kg/s V0 Ejected Fuel = 2500 m/s V0 rocket = 0 m/s

Determine the linear momentum of a person whose mass is 80 kg and who is running at a rate of 3 m/s. Compare it to the momentum of a car that has a mass of 2000 kg and is moving at a rate of 30 m/s in the same direction as the person.

A billiard player sends the cue ball toward a group of three balls that are initially at rest and in contact with one another. After the cue ball strikes the group, the four balls scatter, each traveling in a different direction with different speeds as shown in the figure below. If each ball has the same mass, 0.16 kg, determine the total momentum of the system consisting of the four balls immediately after the collision. (Assume v1 = 0.33 m/s, θ1 = 70°, v2 = 0.49 m/s, θ2 = 30°, v3 = 0.21 m/s, v4 = 0.48 m/s.) magnitude ? (in kg m/s^2) direction ? (in degrees counterclockwise from the + x-axis)

An athlete is holding 36 lb of weights at a height of 6 inches above the stack as shown. To lower the weights, she applies a constant force of 5 lb to the handle. Determine the velocity of the weights immediately before they hit the stack.

30 mg = 1600 kg ma = 1200 kg VA1 = 50 km/h V81 = ? The two cars, A, and B, collided at right angles at the intersection. During the collision, the cars became entangled (AB) and moved off together to bump into a huge old tree. Calculate the velocity (km/h) of car B just before the collision with car A at the intersection. Right after bumping with the tree, determine the new velocity of the "entangled" cars. Also, compute the percent energy lost from the cars after the two collisions occurred. Neglect the geometry of the cars before and after the collision. Coefficient of restitution between the entangled cars (AB) and the tree (C), e43c = 0.18

A railroad car having a mass of 15 Mg is coasting at 1.5 m/s on a horizontal track. At the same time another car having a mass of 12Mg is coasting at 0.75 m/s in the opposite direction. If the cars meet and couple together, determine the speed of both cars just after the coupling. Find the difference between the total kinetic energy before and after coupling has occurred, and explain qualitatively what happened to this energy

A stone was dropped freely from a balloon at a height of 190 m. above the ground. The balloon is moving upward at a speed of 30 m/s. Determine the velocity of the stone as it hits the ground.