Beatrice stands at rest on her skateboard. The mass of Beatrice and the skateboard together is 75 kg. Isaac Newton throws a 3.0 kg ball horizontally to the right at 4.0 m/s to Beatrice, who catches it.  (a)  What is the final speed of Beatrice and the skateboard? (b)  How much mechanical energy was lost in the process?

A 7,300-kg truck runs into the rear of a 1,000-kg car that was stationary. The truck and car are locked together after the collision and move with speed 8 m/s. Compute how much kinetic energy was "lost" in this inelastic collision.  answer using J (JOULE)

A railroad car of mass 2.55  104 kg is moving with a speed of 3.94 m/s. It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 1.97 m/s. (a) What is the speed of the four cars after the collision? (Round your answer to at least two decimal places.)  (b) How much mechanical energy is lost in the collision?

In a railroad accident, a boxcar weighing 200 kN and traveling at 2.00 m/s on horizontal track slams into a stationary caboose weighing 440 kN. The collision connects the caboose to the boxcar. How much energy is transferred from kinetic energy to other forms of energy in the collision?

Timmy is sat down in class, looking around the room. He notices a water bottle on a desk next to him and thinks to himself that since the water bottle is on the desk it must not have kinetic energy. Is he right yes, or no? Explain?

Jane and Jake are looking at what happens to body 1 of mass m and body 2 of mass 2m, initially at rest, when equal forces are applied separately to the two bodies. Jake says that equal forces applied for equal times do equal amounts of work on the two bodies. Jane says that the two forces do equal amounts of work only if the two bodies move equal distances in the direction of the forces. Which one, if either, is correct? O Jake, because the speed of body 1 is half the speed of body 2, but m¡v1= m2V2- O Jane, because work does not depend on mass, only on force times distance. O Jake, because all bodies travel equal distances when equal forces are applied for equal times. O Jane, because it takes the same time for all bodies to travel equal distances when equal forces are involved. O Neither, because we can't compare the amounts of work done on bodies of different mass.

A running man has half the kinetic energy of a boy half his mass. The man speeds up by 1.0m/s and then has the same kinetic energy as the boy. What were the original speeds of (a) the man and (b) the boy?

Ronaldo is playing outside and shoots a ball of mass 2 kg horizontally with a speed of 8.0 m/s toward a green cart. The mass of the green cart is 15 kg and it rolls at a speed of 1.0 m/s along a horizontal path with no friction. The ball gets stuck in the card. What is the velocity of the cart after the ball strikes it? What are the initial and final kinetic energies of the system? Is the energy conserved in this collision process? What type of collision process is it?

A bullet is fired into a large stationary absorber and comes to rest. Temperature measurements of the absorber show that the bullet lost 2110 J of kinetic energy, and high-speed photos of the bullet show that it was moving at 915 m/s just as it struck the absorber.   What is the mass of the bullet?

A particle of mass m has a velocity of v = (v₂i + vj + v₂k). What is the correct expression for its kinetic energy? O a. O b. O c. O d. O e. m(v2i+vy²j + v₂²k)/2 None of these choices. m(vx2 + Vy² + V₂²)/2 m/2(2vx + 2Vy + 2V₂) m/2(2v,i + 2vj + 2v₂k)