4. How long would it take for a water balloon to fall 39 m if we dropped it starting from rest down an elevator shaft from the 13th floor? Ignore air resistance and use a = -9.8 m/s2.
x, = x + vt + (1/2) a t?

Which of the following explains why it took so long for the public to accept the negative health effects of smoking? a)people were waiting for counter reasons, and those were presented.b)scientists had not completely finalized their results, which took 30 years.c)cigarettes were cheaply available and media channels were very inefficient.d)cigarette manufacturers were trying hard to bring an alternative into the market

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

Determine the net charge of the predominant form of arg at (a) ph 1.0, (b) ph 5.0, (c) ph 10.5, and (d) ph 13.5