When the speed of your car is doubled, by what factor does its kinetic energy increase?
(a) square root of 2 .
(b) 2.
(c) 4.
(d) 8.
Ans: (c) 4.
You might also like to view...
A cup that is 6.0 cm tall is in front of a concave lens. The image of the cup is 2.5 cm tall and 7.5 cm from the lens. What is the focal length of the lens?
A) -6.0 cm B) -7.5 cm C) -13 cm D) +18 cm E) +6.0 cm
Two objects of different mass are released simultaneously from the top of a 20-m tower and fall to the ground. If air resistance is negligible, which statement best applies?
a. The greater mass hits the ground first. b. Both objects hit the ground together. c. The smaller mass hits the ground first. d. No conclusion can be made with the information given.
Estimate the time required to heat the center of a 1.5-kg roast in a 163°C oven to 77°C. State your assumptions carefully and compare your results with cooking instructions in a standard cookbook.
GIVEN
FIND
The time required to heat the roast
ASSUMPTIONS
SKETCH
If the voltage across a circuit of constant resistance is doubled, the power dissipated by that circuit will
A) be four times as large. B) be two times as large. C) decrease to one-half the original power. D) decrease to one-fourth the original power.