Question

1. A 2.33 kg ball is dropped from a height of 3 m.  The ball then bounces back upward a distance of 2.2 m. How much energy was lost in the collision with the ground?

   		50.2 J
   		18.3 J
   		68.5 J
   		118.7 J

A 2.33 kg ball is dropped from a height of 3 m.  The ball then bounces back upward a distance of 2.2 m. How much momentum does the ball have immediately after bouncing off the ground?

		5.13 kg m/s
		21.6 kg m/s
		15.3 kg m/s
		17.4 kg m/s

A 2.33 kg ball is dropped from a height of 3 m.  The ball then bounces back upward a distance of 2.2 m. What is the speed of the ball immediately after bouncing off the floor?

		5.13 m/s
		8.24 m/s
		21.6 m/s
		6.57 m/s

A 2.33 kg ball is dropped from a height of 3 m. What is the magnitude of its momentum the moment before hitting the floor?

		7.67 kg m/s
		0 kg m/s
		17.9 kg m/s
		22.8 kg m/s

A 2.33 kg ball is dropped from a height of 3 m. How fast is it going right before it strikes the ground?

		7.67 m/s
		22.9 m/s
		0 m/s
		29.4 m/s

Answer 1

1.

Mass of ball,m=2.33 kg

Initial height,hi=3m

Final height,hf=2.2 m

Energy lost in the collision with the ground=mghi-mghf=2.339.8(3-2.2)=18.3 J

2.

Momentum of ball after bouncing off the ground=m(2ghf)1/2=2.33(29.82.2)1/2=15.3 kg m/s

3.

Speed of the ball immediately after bouncing off the floor=(2ghf)1/2=(29.82.2)1/2=6.57 m/s

4.

Magnitude of its momentum the moment before hitting the floor=m(2ghi)1/2=2.33(29.83)1/2=17.9 kg m/s

5.

Speed of the ball  before it strikes the ground=(2ghi)1/2=(29.83)1/2=7.67 m/s