1. A ball (m= 0.4kg) is moving toward a wall ( V₁ = 10 m/s) and after a collision, will return

with V₂ = 8 m/s ( Opposite direction)

What is the impulse force (F) if the collision time was t = 0.001 s

		F =800N
		F =-800N
		F =-7200N
		F = 7200N

2.If you release a ball at the height =20m,after falling down toward the earth and having an elasticcollision with the earth,what is the final height on its path(after collision with the earth)

(Round in two decimal places and do not use comma and unit)

Maximum height =[ ]m

3. How much energy do we need to add to 12Kg of water to increase its temperature from 320 Kto 365 K?

( Specific Heat for Water C = 4186 j/kg K)

		226.044 J
		2260.44 J
		2260440 J
		226044 J

4. What is the kinetic energy of a car ( mass = 2360 kg) with a speed of v = 21 m/s

( round the final answer in two decimal places, do not use comma and unit)

5. Consider two systems: Acup of coffee( 60^oC) and Seawater(30^oC)

Which one has higher energy?

Does the Heat energy flow from cup to sea or from sea to water?

	a	Cup has more energy and energy willtransferfrom Cup to Sea
	b	Seawater has a lower temperature butmore energyand energy willtransferfrom Cup to Sea
	c	Seawater has a lower temperature and loweramount ofenergyand energy willtransferfrom Cup to Sea
	d	Seawater has a lower temperature butmore energyand energy willtransferfrom sea to cup