... ball is greatest at greatesat height. b)by the principle of conse: of energy the total energy of the ball is constant throughout its motion. c)by the principle of consev: momentum the momentum of ball is constant throughout its motion. d)the potential energy of the ball increases uniformly with time during ascend
A ball is thrown vertically upward. Neglecting air resistance ,which statement is true? a)K.E of?
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- 3+ months ago by anonymous...
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- air, ball, motion, energy, resistance, height, upward, statement
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Answers (1)
Energy is not a physical unit. It is a philosophical concept and an accounting technique used to analyze mechanical and chemical exchanges. In nuclear physics it is defined as a wavelength of light, in biology it is a synonym for metabolism, and in public utilities they say energy when they mean connectivity. Anybody who uses the word in any other context either does not know what he is talking about, or is peddling something you don't need.
Physics and math are almost the same subject. When we say total energy is constant, we only mean that the accounting expression KE + PE stays the same number.
a. KE means motion, and that is zero at greatest height, so this is false.
b. This is true.
c. Momentum is the product of mass and velocity, and velocity is changing, so this is false.
d. h = (1/2)gt^2 -- Potential energy varies as the square root of time.