A rock is thrown downward from an unknown height above the ground with an initial speed of 10 m/s. It strikes the ground 3.0 s later. Determine the initial height of the rock above the ground
a. 44 m
b. 14 m
c. 74 m
d. 30 m
e. 60 m
C
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The quantum mechanical model of the hydrogen atom requires that if the orbital quantum number = 4, there are permitted how many possible substates?
a. 22 c. 8 b. 18 d. 32
Starting from rest, a car accelerates down a straight road with constant acceleration a for a time t, then the direction of the acceleration is reversed, (i.e., it is ?a), and the car comes to a stop in an additional time t, the time for the whole trip being 2t. At what time, or times, is the average velocity of the car for the trip equal to its instantaneous velocity during the trip?
a. There is no such time. b. It is at the halfway point at t. c. This occurs at 2 times, 0.5t and 1.5t. d. This occurs at 2 times, 0.707t and 1.293t.
A shell and tube heat exchanger consists of one shell with 100 thin-walled tubes of 15 mm diameter in a double pass arrangement. The total surface area is 45 m^2 and the overall heat exchanger conductance is 200 W/m^2?K. Water enters the tubes at 15ºC and 6.5 kg/s. Hot gases having properties of air at 200ºC and 5 kg/s flow through the shell. Determine (a) gas outlet temperature and (b) water outlet temperature.
What will be an ideal response?
Energy in Capacitors: A 5.0 ?F capacitor has a potential difference of 5.0 V applied across its plates. If the potential difference across its plates is increased to 8.0 V, how much additional energy does the capacitor store?
A. 98 ?J B. 200 ?J C. 23 ?J D. 45 ?J