Dallas says that any change in velocity is directly proportional to the time interval over which the change took place. Dana says that is true only when the acceleration is constant. Which one, if either, is correct?
A.
B.
so that ?vx = ?t. C.
always is equal to 
.D.
E.
Answer: A
You might also like to view...
A spaceship, moving away from the Earth at a speed of 0.9c, shines a green laser backwards at Earth. An observer on Earth would see the light arriving at a speed of
A. c but at a smaller frequency. B. more than c but less than 1.9c. C. 1.9c and with a shorter wavelength. D. c but at a shorter wavelength. E. 0.1c and with an inverted frequency.
The James Webb Space Telescope is scheduled to launch in 2018. In what range of the electromagnetic spectrum will it operate?
A) X-ray B) Gamma-ray C) Infrared D) Radio
In a helium-neon laser the emissions occur from transitions between two excited states in neon, one being at 20.66 eV above the ground state and the other being 18.70 eV above ground. What is the energy of the photons emitted by this laser?
A) 20.66 eV B) 1.96 eV C) 18.70 eV D) 19.60 eV E) 39.36 eV
In different experimental trials, an electron, a proton, or a doubly charged oxygen atom (O--), is fired within a vacuum tube. The particle’s trajectory carries it through a point where the electric potential is 40.0 V and then through a point at a different potential. Rank each of the following cases according to the change in kinetic energy of the particle over this part of its flight from
the largest increase to the largest decrease in kinetic energy. In your ranking, display any cases of equality. (a) An electron moves from 40.0 V to 60.0 V. (b) An electron moves from 40.0 V to 20.0 V. (c) A proton moves from 40.0 V to 20.0 V. (d) A proton moves from 40.0 V to 10.0 V. (e) An O-- ion moves from 40.0 V to 60.0 V.
1.a > b > c > e > d 2.b > a = c > d > e 3.e > d > a = c > b 4.c > e > a = b > d