1. An 17.5kg mass moving initially at 18.8 m/s bounces off a 12.5 Kg mass at rest, which subsequently moves co-linearly away from the collision at 18.96m/s. The collision itself has a duration of 4mS. Compute the average force between the two masses during the collision.

2. Two particles of mass m₁ = 6.55kg and m₂ = 3.87kg are traveling along one-dimension with velocities of v₁ = 18.5m/s and v₂ = 0. If they undergo a perfectly elastic collision in one-dimension, then what is the final velocity of (a) the first particle and (b) the second particle?

3. The ballistic pendulum of mass m_p = 0.145kg catches a horizontally fired bullet of mass m_b = 0.00825kg in a perfectly inelastic collision, where the bullet and pendulum arc upward together with a maximum angle of = 33.8^o that is recorded by an observer. Knowing that the arm length to center of mass of the pendulum is L = 0.246m, (a) then what was kinetic energy of the bullet/pendulum system immediately after impact? (b) What was the velocity of the bullet/pendulum system immediately after impact? (c) Knowing that momentum is conserved, what was the initial velocity of the bullet? (d) Find the value for the kinetic energy of the bullet/pendulum system just after impact divided by the kinetic energy of the bullet just before impact, i.e., find K_(b+p)/K_b.