The efficiency of the steam engine is 78.9%.
<h3>What is the efficiency of a machine?</h3>
The efficiency of a machine is a measure of the useful work done by the machine as against the work input into the machine.
- Efficiency of a machine = work output/work input × 100%
Work output of the steam engine = 225 K
Work input of the steam engine = 285 K
The efficiency of the machine = 225/275 × 100% = 78.9%
Therefore, the efficiency of the steam engine is 78.9%.
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Answer:
V = 0.714m/s
Explanation:
Full solution calculation can be found in the attachment below.
From the principle of conservation of linear momentum, the sum of momentum before collision equals the sum of momentum after collision.
Before collision only the train had momentum. After the collision the train and the boxcars stick together and move as one body. The initial momentum of the train is now shared with the boxcars as they move together as one body. The both move with a common velocity v.
See the attachment below for the solution calculation.
Answer:
Explanation:
a)
Ff = μmgcosθ
Ff = 0.28(1600)(9.8)cos(-84)
Ff = 458.9217...
Ff = 460 N
b) ignoring the curves required at top and bottom which change the friction force significantly, especially at the bottom where centripetal acceleration will greatly increase normal forces and thus friction force.
W = Ffd
W = 458.9217(-49.4/sin(-84)
W = 22,795.6119...
W = 23 kJ
c) same assumptions as part b
The change in potential energy minus the work of friction will be kinetic energy.
KE = PE - W
½mv² = mgh - (μmgcosθ)d
v² = 2(gh - (μgcosθ)(h/sinθ))
v = √(2gh(1 - μcotθ))
v = √(2(9.8)(49.4)(1 - 0.28cot84))
v = 30.6552...
v = 31 m/s
Answer:
(a) decrease
Explanation:
Viscosity is the resistance which occur to flow of the fluid.
More the inter molecular forces between particles of the liquid, more the viscosity of liquid.
<u>Effect of temperature on viscosity:-</u>
Viscosity decreases with the increase in the temperature as forces among the particles decrease on increasing temperature. The kinetic energy of the particles of the liquid increases causing to move in more random motions and thus weaker inter molecular forces and this offer less resistance to the flow.
<u>Hence, viscosity of the liquids decrease with the increasing temperature.</u>
