Answer:
a
Explanation:
<u>In order to maintain speed, a moving object or person must move at a constant velocity</u>. Accelerating will increase the speed while decelerating will reduce the speed.
Hence, for Bolt to be able to maintain the top speed for a few seconds, he needs to move at a constant velocity.
The correct option is a.
Answer:Kinetic energy is the energy of motion. All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward. 3. A force is a push or pull that causes an object to move, change direction, change speed, or stop.
Explanation: Not sure if that's what you meant but that's the answer I can give you.
Answer:
a)P₂ =4 bar
b)W= - 1482.48 KJ
It means that work done on the system.
c)S₂ - S₁ = 3.42 KJ/K
Explanation:
Given that
T₁ = 300 K ,V₁ = 3 m³ ,P₁=2 bar
T₂ = 600 K ,V₂=V₁ 3 m³
Given that tank is rigid and insulated.It means that volume of the gas will remain constant.
Lets take the final pressure = P₂
For ideal gas P V = m R T
P₂ =4 bar
Internal energy
ΔU = m Cv ΔT
Cv=0.71 KJ/kg.k for air
m= 6.96 kg
ΔU= 6.96 x 0.71 x (600 - 300)
ΔU=1482.48 KJ
From first law
Q= ΔU + W
Q= 0 Insulated
W = - ΔU
W= - 1482.48 KJ
It means that work done on the system.
Change in the entropy
S₂ - S₁ = 3.42 KJ/K
Given the fact that energy conversion is not entirely efficient, it is impossible to produce a perpetual motion machine.
<h3>What is a perpetual motion machine?</h3>
The perpetual motion machine in one that is able to work continuously without stopping. This would mean that the efficiency of this machine must that the machine is 100% efficient which violates the second law of thermodynamics.
Thus, given the fact that energy conversion is not entirely efficient and energy looses cause machines not function effectively, it is impossible to produce a perpetual motion machine.
Learn kore about a perpetual motion machine:brainly.com/question/13001849
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