Hello I need help on question 7,8,9, and 10 provided in the images. Thank you so much!

7. [11 Points] SERPSE10 9.4.0P.017. 0/6 Submissions Used ASK YOUR TEACHER Two blocks are free to slide along the frictionless wooden track shown below. The block of mass m1 = 4.91 kg is released from the position shown, at height h = 5.00 m above the flat part of the track. Protruding from its front end is the north pole of a strong magnet, which repels the north pole of an identical magnet embedded in the back end of the block of mass m2 = 9.90 kg, initially at rest. The two blocks never touch. Calculate the maximum height to which m1 rises after the elastic collision. :m Need Help? __ 8. [-I2 Points] SERPSE10 9.4.P.015. 0/6 Submissions Used ASK YOUR TEACHER A car of mass m moving at a speed V1 collides and couples with the back of a truck of mass 4m moving initially in the same direction as the car at a lower speed V2. (Use any variable or symbol stated above as necessary.) (a) What is the speed i/f of the two vehicles immediately after the collision? Vf= (b) What is the change in kinetic energy of the cartruck system in the collision? AK: 9. [-/1 Points] SERPSE10 9.4.P.016. 0/6 Submissions Used ASK YOUR TEACHER A 7.00 g bullet, when fired from a gun into a 1.00 kg block of wood held in a vise, penetrates the block to a depth of 6.80 cm. This block of wood is next placed on a frictionless horizontal surface, and a second 7.00 g bullet is fired from the gun into the block. To what depth will the bullet penetrate the block in this case? Cm Need Help? 10. [/2 Points] SERPSE10 9.4.P.017.MI. 0/6 Submissions Used ASK YOUR TEACHER A tennis ball of mass 57.0 g is held just above a basketball of mass 567 9. With their centers vertically aligned, both balls are released from rest at the same time, to fall through a distance of 1.35 m, as shown in the figure below. @l. (a) Find the magnitude of the downward velocity with which the basketball reaches the ground. :1 m (b) Assume that an elastic collision with the ground instantaneously reverses the velocity of the basketball while the tennis ball is still moving down. Next, the two balls meet in an elastic collision. To what height does the tennis ball rebound? :l m Need Help