Question

I ONLY NEED PART B ANSWERED. EVERYTHING ELSE IS LISTED FOR INFO PURPOSES

A. An object of mass m1 = 17 kg and velocity v1 = 6.5 m/s crashes into another object of mass m2 = 5 kg and velocity v2 = −14.5 m/s. The two particles stick together as a result of the collision. Because no external forces are acting, the collision does not change the total momentum of the system of two particles, so the principle of conservation of linear momentum applies. m1v1i + m2v2i = (m1 + m2)vf If Jed and Kadia use the one-dimensional conservation of momentum equation to find the final velocity of the two joined objects after the collision, what do they obtain? (Indicate the direction with the sign of your answer.)

=1.73

B. Analyze Although the forces that the two objects exert on each other cannot change their total momentum, they can change the total kinetic energy in an inelastic collision such as the one being considered. All of the mechanical energy in the problem is kinetic energy. Change in kinetic energy is given by ΔK = 1/2(m1 + m2)vf^2 −(1/2m1v1i^2+ 1/2m2v2i^2) What do Jed and Kadia find for the change in the total mechanical energy of the system?

Answer 1

Initial kinetic enegry is the sum of the kinetic energies of indivisual bodies

As the two masses stick togather, final mass is 17 kg + 5 kg = 22 kg

Final Velocity is calculated is 1.73 m/s

Final kinetic energy is

Change in Mechanical energy = Change in kinetic energy = final - initial

= 65.84 J - 884.75 J = -818.91 J

The -ve sign is because enrrgy is lost.