An outfielder throws a baseball with an initial speed of 81.8mi/h. Just before an infielder catches the ball at the same level,
the ball’s speed is 110 ft/s. In foot-pounds, by how much is the mechanical energy of the ball– Earth system reduced because of air drag? (The weight of a baseball is 9.0 oz.)
1 answer:
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The complete question is as follows:
A 0.150-kg toy is undergoing SHM on the end of a horizontal spring with force constant k = 300 N/m. When the toy is 0.0120 m from its equilibrium position, it is observed to have a speed of 0.400 m/s.
Answer:
The correct answer is 0.034 J.
Explanation:
Given :
mass of the toy is m = 0.15 kg.
The force constant of restoring force k = 300 Nm⁻¹
When the position of the toy from the equilibrium is x = 0.012m, then the
speed of the toy vx = 0.4m s
The total mechanical energy in SHM is given by
E= 1/2 (mv²+ kx²) = 1/2 kA²
(here, m = mass of the object, vx = velocity, k = force constant
of restoring force, and A = amplitude of SHM.)
Hence by substituting the numerical values in equation 1, we get
= 0.034 J
Thus, the correct answer is 0.034 J.
Answer:
The value of total energy needed per minute for the humidifier = 77.78 KJ
Explanation:
Total energy per minute the humidifier required = Energy required to heat water to boiling point) + Energy required to convert liquid water into vapor at the boiling point) ----- (1)
Specific heat of water = 4190
The heat of vaporization is = 2256
Mass = 0.030 kg
Energy needed to heat water to boiling point =
Energy needed to heat water to boiling point = 0.030 × 4.19 × (100 - 20)
Energy () = 10.08 KJ
Energy needed to convert liquid water into vapor at the boiling point
= 0.030 × 2256 = 67.68 KJ
Thus the total energy needed E = +
E = 10.08 + 67.68
E = 77.78 KJ
This is the value of total energy needed per minute for the humidifier.