Suppose that for a couple you were told that the girls mass was two-thirds of the boys mass. The boy has a velocity of v=0.66m/s to the left. What would be the girls velocity in this case

4) Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, the first having a mass of 150,000 kg and a velocity of 0.300 m/s, and the second having a mass of 125,000 kg and a velocity of −0.120 m/s. (The minus indicates direction of motion.) What is their final velocity (in m/s)? _____ m/s

During a car collision, the knee, thighbone, and hip can sustain a force no greater than 4000 NN. Forces that exceed this amount could cause dislocations or fractures. Assume that in a collision a knee stops when it hits the car's dashboard. Also assume that the mass of the body parts stopped by the knee is about 20% of the total body mass. The person with a mass of 90 kgkg is initially traveling at 18 m/sm/s (40 mi/hmi/h).  What minimum stopping time interval in needed to avoid injury to the knee?  What is the minimum stopping distance?

An astronaut of mass 65.0 kg is at rest relative to her space vehicle with nothing behind her except the empty,dark, vacuum of space. Another astronaut decides to play a practical joke on her and throws a 10.0 kg anvil(because those are totally used in space) at her with a velocity of 3.00 m/s. How fast do she and the anvil moveonce she catches it? Just to lower your anxiety, there is a way for her to get back to the space vehicle

4. A rocket accelerates by burning its onboard fuel, so that its mass decreases with time.Suppose that the initial mass of the rocket at liftoff (including its fuel) is m, the fuel isconsumed at rate r, and the exhaust gases are ejected with constant velocity ν (relativeto the rocket). A model for the velocity of the rocket at time t is given by the equationv(t) = −ν ln(1 −Rt) −gt,where g is the acceleration due to gravity, R = r/m, and t is not too large.(a) Find an expression for the acceleration, a(t) = v′(t), of the rocket at any time t.(b) Find an expression for the position of the height, h(t), of the rocket at any timet. You can assume that at t = 0, the rocket hasn’t left the ground. Hint: re-member that ν,R,g are all constants and t is the independent variable.Write out your steps carefully!(c) Let g = 9.8 m/s2, R = 0.005 s−1. What does the velocity of the exhaust gases,ν, need to be for the rocket to reach a height of 6000 m one minute after liftoff?You can round to the…

On a horizontal frictionless table, masses A and B (3 kg, 5 kg) slide to the right and left, respectively. They have speeds of 3 m/s and 1 m/s, respectively. The two masses collide, and bounce off each other. After the collision, they travel in opposite directions at speeds of 1.5 m/s and 1.700 m/s, respectively. (Note:In this problem, please use + dir = right, - dir = left, to indicate direction.) a.) Calculate A's momentum: before collision: kg-m/s after collision: kg-m/s Make sure you understand why it is NOT conserved. b.) Calculate B's momentum: before collision: kg-m/s after collision: kg-m/s Make sure you understand why it is NOT conserved. c.) Calculate the A+B system's momentum: before collision: kg-m/s after collision: kg-m/s Make sure you understand why it IS conserved. d.) Calculate the kinetic energy of the A+B system: before collision: after collision: J What kind of collision is this v ---Select--- elastic somewhat inelastic Submit Answer completely inelastic

Train cars are coupled together by being bumped into one another. Supposed to loaded train cars are moving toward one another, the first having a mass of 130,000 KG and the velocity of 0.300 M/S, and the second having a mass of 135,000 KG and I velocity of -0.120M/S. (The minus indicates direction of motion.) what is their final velocity? m/s ?