A 10-kg rock and 20-kg rock are dropped from the same height and there is no air. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground?

A) 4T
B) 2T
C) T
D) T/2
E) T/4


C

Physics & Space Science

You might also like to view...

Two 1.5 m-square and parallel flat plates are 30 cm apart. Plate A1 is maintained at a temperature of 1100 K and A2 at 500 K. The emissivities of the plates are 0.5 and 0.8, respectively. Considering the surroundings black at 0 K and including multiple inter-reflections, determine (a) the net radiant exchange between the plates and (b) the heat input required by surface A1 to maintain its temperature. The outer-facing surfaces of the plates are adiabatic.

GIVEN
? Two square parallel flat plates, 30 cm apart
? Temperature of A1 (T1) = 1100 K
? Temperature of A2 (T2) = 500 K
? Emittances: ?1 = 0.5 ?2 = 0.8
? Surroundings are black at (T3) = 0 K
FIND
Including multiple inter-reflections, determine:
(a) The net radiant exchange (q1–2)
(b) The heat input at surface A1 (q1) required to maintain its temperature
SKETCH

PROPERTIES AND CONSTANTS

Physics & Space Science

A parallel plate capacitor has the voltage applied to it doubled. Is the force between the plates attractive or repulsive, and what happens to the force between the plates when the voltage is doubled?

a. The force is attractive and it quadruples. b. The force is attractive and it doubles. c. The force is repulsive and it halves. d. There is no force between the plates since the net charge is zero on the capacitor.

Physics & Space Science

Like charges _________, unlike charges __________

Fill in the blank(s) with correct word

Physics & Space Science

______ media begins playing as the server delivers the file to the computer or device.

A. Embedded B. Streaming C. Virtual D. Open source

Physics & Space Science