Your friends says the helium in your birthday helium comes from radioactive decays. What is your response?

A basketball player achieves a hang time of 0.773 s in dunking the ball. What vertical height will he attain? The acceleration of gravity is 9.8 m/s^2 .

A student throws a baseball upwards at an angle of 60 degrees to the horizontal. The initial horizontal and vertical components are 12.5 m/s and 21.7 m/s, respectively.

A car travelling at 45 mi/hr (20.1 m/s) comes to rest in 4 seconds. Find the acceleration of the car in m/s2.

When the volleyball rises in the air, what does the force of gravity cause the volleyball to do

If a force of 12 N is applied to an object with a mass of 2 kg, the object will accelerate at A. 0.17 m/s2. B. 24 m/s2. C. 6 m/s2. D. 12 m/s2.

Janice has just measured the density of an object. Which value is possible? (Density: D = )

Based on how the book describes a heat pump in sec 16.3 how does a heat pump prove law of conservation of energy

When a gas in a container is squeezed to half its volume, its density?

A ballet student with her arms and a leg extended spins with an initial rotational speed of 0.90rev/s. As she draws her arms and leg in toward her body, her rotational inertia becomes 0.80 kg⋅m2 and her rotational velocity is 4.1rev/s.

The power rating of a vacuum cleaner is 0.8 kilowatts. If you use the vacuum cleaner for 2.5 hours, how much energy does it use?