Answer:
The change in kinetic energy is 4.3875 kJ
The amount of energy transferred by heat for the process is -66.98 kJ
Explanation:
Given;
mass of the system, m = 13 kg
change in height, Δh = -50 m
initial velocity, u = 15 m/s
final velocity, v = 30 m/s
change in internal energy per mass, ΔU = -5 kJ/kg
The change in kinetic energy is given by;
ΔK.E = K.E₂ - K.E₁
ΔK.E = ¹/₂mv² - ¹/₂mu²
ΔK.E = ¹/₂m(v² - u²)
ΔK.E = ¹/₂ ₓ 13 (30² - 15²)
ΔK.E = 4387.5 J
ΔK.E = 4.3875 kJ
The amount of energy transferred by heat for the process;
Q = W + ΔP.E + ΔK.E + ΔU
Where;
ΔP.E = mgΔh
ΔP.E = 13 x 9.8 x (-50)
ΔP.E = -6370 J = -6.37 kJ
W = 0
ΔU = -5kJ/kg x 13kg
ΔU = -65 kJ
Q = W + ΔP.E + ΔK.E + ΔU
Q = 0 + (-6.37) + (4.3875) + (-65)
Q = -66.98 kJ
1.39m/s
Explanation:
Given parameters:
Mass of car M₁ = 1000kg
Velocity V₁ = 2.5m/s
Mass of second car M₂ = 1800kg
Unknown:
Velocity of second car V₂ = ?
Solution:
For the other body to come to rest, the momentum of the colliding cars must be equal and in the opposite direction:
Momentum of car 1 - momentum of car 2 = 0
Momentum of car 1 = Momentum of car 2
M₁V₁ = M₂V₂
The unknown is V₂
1000x2.5 = 1800V₂
V₂ = 
= 1.39m/s
Learn more:
Momentum brainly.com/question/2990238
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The power of batteries in a circuit. The key functions of a battery and bulb in a circuit are explained. A battery is a source of energy which provides a push - a voltage - of energy to get the current flowing in a circuit. A bulb uses the electrical energy provided by the battery, but does not use current.
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Answer: Neither Sandra nor Marissa will be in her THR zone.
Explanation:
1) Actual pulse of both Sandra and Marissa : 144 bpm
2) Decrease of 20 bpm ⇒ 144 bpm - 20 bpm = 124 bpm
3) Sandra's TRH is in the range 135 - 172 bpm.
Since 124 < 135, she will be below the range.
4) Marissa's TRH range is 143 - 176 bpm.
Since, 124 < 143, she is below the range
In conlusion, neither Sandra nor Marissa will be in her THR zone.
yes ,each piece will remain a magnet because the small pieces will cut into north and south
