An 85-kg football player is running at 7.0 m/s and makes perfectly inelastic collision with a 105-kg linebacker that is at rest. How much Kinetic Energy is lost?

A 1.72 kg block of soft wood is suspended by two strings from the ceiling. The wood is free to rotatein pendulum-like fashion when a force is exerted upon it. An 8.5 g bullet is fired into the wood. Thebullet enters the wood at 431 m/s and exits the opposite side shortly thereafter. If the wood rises to aheight of 13.8 cm after the collision, then what is the exit speed of the bullet?

A small songbird with a mass of 0.015 kg is standing on a branch. A falcon with a mass of 0.810 kg catches the song bird in the air while flying horizontally with a velocity of 8.30 m/s. How much kinetic energy is lost in the collision when the falcon catches the songbird ( both fly off horizontally in the same direction as the falcon? Express your answer to two decimal places in units of Joules, but do not include units in your answer.

A 1200-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 9 000-kg truck moving in the same direction at 20.0 m/s (Fig. P6.44). The velocity of the car right after the collision is 18.0 m/s to the east. (a) What is the velocity of the truck right after the collision? (b) How much mechanical energy is lost in the colli- sion? Account for this loss in energy. +20.0 m/s +25.0 m/s +18.0 m/s Before After Figure P6.44

The froghopper holds the title of the best jumper of the animal world. A 0.0198gram froghopper can accelerate at 4,000 m/s2 over 2.0 mm as it jumps. What is the impulse delivered to the froghopper as it makes this jump?

I don't understand this hw problem.

A blob of clay and a tennis ball are thrown at a partially open door in order to try to close it. Both have the same mass. The blob of clay sticks to the door while the tennis ball bounces off. Which one will be more likely to close the door or will they both close the door by the same amount?

A small songbird with a mass of 0.020 kg is standing on a branch. A falcon with a mass of 0.890 kg catches the song bird in the air while flying horizontally with a velocity of 8.70 m/s. How much kinetic energy is lost in the collision when the falcon catches the songbird (both fly off horizontally in the same direction as the falcon? Express your answer to two decimal places in units of Joules, but do not include units in your answer.

A 200,000 kg railroad car moving at 3.00 m/s couples up with (sticks together) with another 150,000 kg car at rest.  What is the final speed of the two cars immediately after the collision?

A railroad car of mass 2.56 x 104 kg is moving with a speed of 4.10 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 2.05 m/s. (a) What is the speed of the four cars after the collision? (Round your answer to at least two decimal places.) m/s (b) How much mechanical energy is lost in the collision?