What is the magnitude of the vertical electric field that will balance the weight of a plastic sphere of mass 2.1g that’s been chargers to -3.0nC? (k=9.0x10^9 N•m^2/C^2

Using the work energy theorem. what is the velocity of a 850kg car after starting at rest when 13,000j of work is done to it.

A2.00-m long piano wire with a mass per unit length of 12.0 g/m is under a tension of 8.00 kn. what is the frequency of the fundamental mode of vibration of this wire?

A0.750 kg aluminum pan is removed from the stove and plunged into a sink filled with 10.0 kg of water at 293 k. the water temperature quickly rises to 297 k. what was the initial temperature of the aluminum pan? the specific heat of aluminum is ca = 900 j/(kgk) and water is cw = 4190 j/(kgk)