Answer:
a) m = 69.0 kg
b) release some gas in the opposite direction to the astronaut's movement
Explanation:
a) Let's use Newton's second law
F = m a
m = F / a
m = 60.0 / 0.870
m = 69.0 kg
b) when we exert a force on the astronaut it acquires a momentum po, as the astronaut system plus spacecraft is isolated, the momentum is conserved
p₀ = p_f
m v = M v '
v ’=
so we see that the ship is moving backwards, but since the mass of the ship is much greater than the mass of the astronaut, the speed of the ship is very small.
One method to avoid this effect is to release some gas in the opposite direction to the astronaut's movement so that the initial momentum of the astronaut plus the gas is zero and therefore no movement is created in the spacecraft.
The smaller body will have greater temperature change.
<h3><u>Explanation</u>:</h3>
Temperature is defined as the degree of hotness or coldness of a body. The relationship of the temperature with heat is described as
Q =m c dT.
Where Q is the heat content
m is the mass of body
c is the specific heat of body
dT is the temperature change of body.
Here the bodies are made up of same substance, so specific heat is same. The mass of bigger body is M and smaller body is m.
So the temperature change of the body will be dependent on the mass of the body. Heat loss by one body will be equal to heat gained by the other.
So M dT1 = mdT2.
So, M/m = dT2 / dT1.
So the the smaller body will be suffering higher temperature change.
Value of resistor = (12V) /(1.2 x 10^-3A)=10000ohms=10k ohms