Heat energy caused by friction is usually a waste product that results when energy is destroyed or dissappears.
Friction converts useful kinetic energy into thermal energy or heat. Friction gets a bad rap for turning useful energy into useless energy.
Answer:
e = 0.0898m
v = 2.07m/s
Explanation:
a) According to Hooke's law
F = ke
e is the extension
k is the spring constant
Since F = mg
mg = ke
e = mg/k
Substitute the given value
e = 1.1(9.8)/120
e = 10.78/120
e = 0.0898m
Hence it is stretched by 0.0898m from its unstrained length
2) Total Energy = PE+KE+Elastic potential
Total Energy = mgh +1/2mv²+1/2ke²
Substitute the given value
5.0= 1.1(9.8)(0.2)+1/2(1.1)v²+1/2(120)(0.0898)²
Solve for v
5.0 = 2.156+0.55v²+0.48338
5.0-2.156-0.48338= 0.55v²
2.36 =0.55v²
v² = 2.36/0.55
v² = 4.29
v ,= √4.29
v = 2.07m/s
Hence the required velocity is 9.28m/s
Answer: touch the pan to the burner
Explanation:
There are three modes of heat transfer:
conduction, convection and radiation.
For conduction, the heat transfers from a hot object to a cold object when the two are in contact.
For convection there is bulk motion of fluid occurs which transfers the heat.
For heat transfer by radiation, medium is not required.
Thus, to demonstrate conduction between pan and burner, the pan must touch the burner.
The answer is b 12N because
We know that<span>
W = F × d × c o s(θ)</span>
assuming theta=0 we then solve and have<span>
F=<span>W/d</span></span>
substitute known values to get:<span><span>
F=<span><span>60J/</span><span>5m</span></span>=12N</span></span>
Answer:
Star A is brighter than Star B by a factor of 2754.22
Explanation:
Lets assume,
the magnitude of star A = m₁ = 1
the magnitude of star B = m₂ = 9.6
the apparent brightness of star A and star B are b₁ and b₂ respectively
Then, relation between the difference of magnitudes and apparent brightness of two stars are related as give below: 
The current magnitude scale followed was formalized by Sir Norman Pogson in 1856. On this scale a magnitude 1 star is 2.512 times brighter than magnitude 2 star. A magnitude 2 star is 2.512 time brighter than a magnitude 3 star. That means a magnitude 1 star is (2.512x2.512) brighter than magnitude 3 bright star.
We need to find the factor by which star A is brighter than star B. Using the equation given above,
Thus,
It means star A is 2754.22 time brighter than Star B.
