Answer:
b) the density of the balloon is less than the density of the atmosphere.
Explanation:
We must take into account that density is defined as the relationship between mass and volume.
The helium density is 0,1785 [kg/m3]
The air density is 1.2 [kg/m3]
Therefore a substance with lower density (helium) will try to rise on substances with heavier density (air).
An example of this is when we mix water with oil, the water is heavier than the oil, that is, the density of the water is greater than the density of the oil, therefore the oil will be located on the surface of the water and not at the bottom.
Another example is that of a balloon inflated with air is common, this balloon doesn't rise because the air density outside the balloon equals the air density inside the balloon, the balloon will fall to the ground since it contains the weight of the air contains the weight of the material of the balloon.
The process by which the heat energy is transmitted between the atoms or molecules is known as conduction.
Explanation:
Conduction is the transfer of heat through the material that are caused by temperature gradient with the material ends in heat flux. The heat transfer done by movement and mixing of a fluid is known as convection.
If a fluid is taken and it is kept as stationary. If there is a temperature gradient across that fluid, there would be transfer of heat that occurs in the fluid. It is negligible when compared to convective heat transfer.
Because of the heat transfer from solid to solid, density of liquid changes and start to move in upward direction due to low density. This type of motion is known as convection currents.
Answer:
Explanation:
Given that,
The length of the beam L = 3.10m
The mass of the steam beam 
= 430kg
The mass of worker 
= 69.0kg
The distance from the fixed point to centre of gravity of beam = 
and our length of beam is 3.10m
so the distance from the fixed point to centre of gravity of beam is
Then the net torque is
is the weight of steel rod
is the weight of the worker
Torque can now be calculated
≅ 9169Nm
<h3>Therefore,the magnitude of the torque is 9169Nm</h3>
The answer is C. Convection.
Radiation is the transfer of energy through electromagnetic waves. Conduction, on the other hand, is energy transfer through solid material. Condensation occurs when warm gas makes contact with a cold surface or environment, which causes a change in state from gas to liquid. These definitions rule out choices A, B, and D.
Convection is movement of particles in fluid or gas. As liquid/gas heats up, it becomes less dense and rises, moving away from the heat source. When it rises, it eventually cools down and sinks again. It is warmed up again and the cycle continues. This is why there is a circular motion when convection occurs.
Explanation:
μ = coefficient of friction.
F = Frictional force = 12N
R = Normal reaction = mg = Weight = 240N
m = mass
g = acceleration due to gravity ≈ 9.8ms—²
μ = F/R
<em>μ </em><em>=</em><em> </em><em>1</em><em>2</em><em>/</em><em>2</em><em>4</em><em>0</em>
<em>μ </em><em>=</em><em> </em>¹/20
μ = 0.05
