A spring stretches 2.0 cm when a 500 g mass is hung from one end. a) What is the spring constant?
300 more grams are added to make the mass a total of 800g
b) What is the total amount of stretch now?
c) How much stored potential energy does the spring have now? d) If we start the mass bobbing up and down with simple harmonic motion, what is the frequency of the oscillation in Hz?

Suppose that two tanks, 1 and 2, each with a large opening at the top, contain different liquids. a small hole is made in the side of each tank at the same depth 1.57 m below the liquid surface, but the hole in tank 2 has 2.49 times the cross-sectional area of the hole in tank 1. (a) what is the ratio ρ1/ρ2 of the densities of the liquids if the mass flow rate is the same for the two holes? (b) what is the ratio rv1/rv2 of the volume flow rates from the two tanks? (c) at one instant, the liquid in tank 1 is 14.9 cm above the hole. if the tanks are to have equal volume flow rates, what height above the hole must the liquid in tank 2 be just then?

Acar traveling at 22 m/s starts to decelerate steadily. it comes to a complete stop in 15 seconds. what is it’s acceleration?

How can you increase the strength of an electromagnet?