I belive it could be 6.5 but I could be wrong
Answer:84Nm
Explanation:
force=400N
Distance=0.210m
Workdone=force x distance
Workdone=400 x 0.210
Workdone=84Nm
Answer:
The sun touches earth during daytime and the suns rays heat our earth giving us heat. The sun heating the earth is also considered radiation.
Explanation:
<h2>
Answer: 0.17</h2>
Explanation:
The Stefan-Boltzmann law establishes that a black body (an ideal body that absorbs or emits all the radiation that incides on it) "emits thermal radiation with a total hemispheric emissive power proportional to the fourth power of its temperature":
(1)
Where:
is the energy radiated by a blackbody radiator per second, per unit area (in Watts). Knowing 
is the Stefan-Boltzmann's constant.
is the Surface area of the body
is the effective temperature of the body (its surface absolute temperature) in Kelvin.
However, there is no ideal black body (ideal radiator) although the radiation of stars like our Sun is quite close. So, in the case of this body, we will use the Stefan-Boltzmann law for real radiator bodies:
(2)
Where 
is the body's emissivity
(the value we want to find)
Isolating from (2):
(3)
Solving:
(4)
Finally:
(5) This is the body's emissivity
The tension in the cord is 14.7 N and the force of pull of the cord is 14.7 N, assuming the block is stationary.
<h3>
What is the tension in the cord?</h3>
The tension in the cord is calculated as follows;
T = ma + mg
where;
- a is the acceleration of the block
- g is acceleration due to gravity
- m is mass of the block
T = m(a + g)
T = 1.5(a + 9.8)
T = 1.5a + 14.7
Thus, the tension in the cord is (1.5a + 14.7) N.
If the block is at rest, the tension is 14.7 N.
<h3>Force of the force</h3>
The force with which the cord pulls is equal to the tension in the cord
F = T = m(a + g)
F = (1.5a + 14.7) N
If the block is stationary, a = 0, the tension and force of pull of the cord = 14.7 N.
Thus, the tension in the cord is 14.7 N and the force of pull of the cord is 14.7 N, assuming the block is stationary.
Learn more about tension here: brainly.com/question/187404
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