Answer:-683 cal
Explanation:
Given
Heat released by system Q=-255 cal
as heat released is taken as negative and vice-versa
Work done by system W=428 cal
From First law of thermodynamics
=change in internal Energy

I think B is the most correct, because logically it's harder to bend a stiffer spring than it is to bend a softer one. Also, I don't think length comes into play. So B.
That ratio is called"efficiency". It doesn't need to be a percent.
It can just as well be a fraction or a decimal number.
Answer:
31.42383 m/s
Explanation:
g = Acceleration due to gravity = 9.81 m/s²
= Coefficient of kinetic friction = 0.48
s = Displacement = 0.935 m
= Mass of bean bag = 0.354 kg
= Mass of empty crate = 3.77 kg
= Speed of the bean bag
= Speed of the crate
Acceleration


From equation of motion

In this system the momentum is conserved

The speed of the bean bag is 31.42383 m/s
Answer:
157.9 kg
Explanation:
Density: This can be defined as the ratio of the mass of a body and it's volume.
The S.I unit of density is kg/m³.
From the question,
Density = Mass/volume
D = m/v............................ Equation 1
Where D = Density of gold, m = mass of gold, v = volume of gold.
make m the subject of the equation
m = Dv.................... Equation 2
Since the gold is a cube,
v = l³................... Equation 3
Where l = length of the gold cube.
Substitute equation 3 into equation 2
m = Dl³............... Equation 4
Given: D = 19300 kg/m³, l = 0.2015 m
Substitute into equation 4
m = 19300(0.2015)³
m = 157.9 kg.