Explanation:
Efficiency is defined as the ratio between the useful output over the total amount consumed. 
The fan does 500W of useful work while wasting 300 W. The total power consumption is 800 W (500 + 300).
If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
Given, mass of titanium metal = 144 g
Heat of fusion of titanium metal= 18.7 J/g
Heat of fusion is the amount of heat energy needed to change the state of one gram of a substance from solid to liquid or vice-versa.
Thus, 18.7 J of heat is needed to melt one gram of titanium metal.
Therefore, heat needed to melt 144 g of titanium metal = 18.7×144
= 2692.8 J
Answer:
Explanation:
A.
Given:
Vo = 21 m/s
Vf = 0 m/s
Using equation of Motion,
Vf^2 = Vo^2 - 2aS
S = (21^2)/2 × 9.8
= 22.5 m.
B.
Given:
S = 22.5 + 21 mm
= 22.521 m
Vo = 0 m/s
Using the equation of motion,
S = Vo × t + 1/2 × a × t^2
22.521 = 0 + 1/2 × 9.8 × t^2
t^2 = (2 × 22.521)/9.8
= 4.6
t = 2.14 s
Answer:
The problem occurs with all spherical mirrors.
Spherical mirrors are practical up to about inches in diameter.
Reflecting telescopes use spherical mirrors for apertures up to about 4 ".
Larger aperture telescopes use parabolic mirrors to obtain sharp focus.
