Given :
Mass of box , m = 250 kg.
Force applied , F = 285 N.
The value of the incline angle is 30°.
the coefficient of dynamic friction is .
To Find :
The speed with which the box is moving with, assuming it takes 4 seconds to reach the top of the incline.
Solution :
Net force applied in box is :
Acceleration , .
By equation of motion :
Therefore, the speed of box is 12.04 m/s.
Hence, this is the required solution.
Answer:
980 J, B
Explanation:
Given that.
mass of substance, m = 75 g
initial temperature of system, θ1 = 150° C
final temperature of system, θ2 = 250° C
specific heat capacity, c = 0.13 J/gC
Q = mcΔθ, where
Q = quantity of heat required in J
m = mass of substance in G
c = specific heat capacity of substance in J/gC
Δθ = change in temperature °C
Δθ = θ2 - θ1
Δθ = 250° C - 150° C
Δθ = 100° C
now that we have all our values, what we do next is to substitute and apply all in the initial formula given
Q = mcΔθ
Q = 75 * 0.13 * 100
Q = 7500 * 0.13
Q = 975 J
Thus, we can say they amount of heat required to increase the temperature of 75g of gold, from 150° - 250° is 975 J, which is approximately, 980 J.
Option B
The first law of thermodynamics is similar to the conservation of energy because both state that this element (i.e., energy) is not created/destroyed in the universe.
<h3>What is the first law of thermodynamics?</h3>
The first law of thermodynamics is a popular law in physics that states change in internal energy is equal to the energy added and the work made by a closed system.
Moreover, the law of conservation of energy states that it cannot be created/destroyed in the Universe, which is deeply associated with principles of thermodynamics.
In conclusion, the first law of thermodynamics is similar to the conservation of energy because both state that this element (i.e., energy) is not created/destroyed in the universe.
Learn more about the first law of thermodynamics here:
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