An object with a mass of 7 kg accelerates 5 m/s2 when an unknown force is applied to it. What is the unknown force?

A bicycle rider travels 50.0 Km in 2.5 hours. What is the cyclist's average speed?

Can someone explain how waves form?

When one person shouts at a football game, the sound intensity level at the center of the fi eld is 60.0 dB. When all the people shout together, the intensity level increases to 109 dB.

2. A car accelerates uniformly from + 10.0 m/s to + 50.0 m/s over a distance of 225 m. How long did it take to go that distance? Show all your work, including the equation used, given and unknown quantities, and any algebra required.

Water is to be boiled at sea level (1 atm pressure) in a 30-cm-diameter stainless steel pan placed on top of a 18-kW electric burner.

The first law of thermodynamics states that ΔE = Q - W. Is this also a statement of the principle of conservation of energy? Yes, the heat added and the change in internal energy of the gas equal the work done by the piston.

How can we calculate the density of a sustance that has irregular volume

A two stage rocket leaves its launch pad moving vertically with an average acceleration of 4 m/s2. at 10 s after launch the first stage of the rocket (now without fuel) is released.

A liquid filled sealed system has cylinders with movable pistons on each end. The face of one piston has an area of 5 cm². The other piston has an area of 500 cm² and is supporting a weight of 2 kN on it.

A turntable is spinning on a frictionless axle when a ball of putty is dropped onto it from above. The putty sticks to the turntable when it lands. Is angular momentum conserved for the turntable and putty (the system) during this process?