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.
Answer:
469.6KJ
Explanation:
Heat energy required can be calculated using the formula
H = mc∆t where
m is the mass of the water
c is the specific heat capacity of the water
∆t is the change in temperature of the water
Given m = 9.78kg
c = 4186j/kg-c.
∆t = 52.07°C - 40.82°C
∆t = 11.25°C
H = 9.78 × 4186 × 11.25
H = 460,564.65Joules
= 460.6KJ
Answer:
A: They produce a real image.
Explanation:
The images formed on the retina of the eye for a normal visibility must always be real.
Only a real image can be physically projected on any physical object whereas the virtual images are visible due to reflections.
- The nearsightedness is corrected with the help of a concave lens since it is the condition of the eye lens remaining thick and curved to converge the rays entering the eyes after a shorter distance which results in their image formation even before the retinal surface so to initially diverge them a bit so that they converge on the retinal surface and form the image there we use concave lens. Vice-versa of the above justification in the case of farsightedness.
Answer:
Decreasing in altitude and increasing in velocity
Explanation:
The formula for potential energy is:
where m is mass, g is constant gravitational energy and h is the potential altitude.
The formula for kinetic energy is:
where v is the velocity
Since m,g are constant, to convert from potential energy to kinetic energy, h must decreases while v increases. For example dropping an object from a height.
