A leaf floating down from a tree is an example of an object in free fall.

The sun appears to move through the background stars. This apparent motion would not exist if:_________.

otez555 [7]

Answer:

b) the earth did not orbit the sun

Explanation:

The sun appears to move through the background stars due to parallax . Parallax is a phenomenon when the near object appears to move faster than the distant object . If we travel in a train , the near object like electric poles on rail track or trees and fields nearby appear to move faster against the distant background .

Hence when the earth moves around the sun , the sun appears to move against the background the stars which are far away . Had earth remained stationary at a place on its orbit around the sun , the sun would have appeared stationary against the background the stars .

3 0

3 years ago

On my science test, there is a bonus question that I want to get right. Why would it be a bad idea to skydive on the moon? Hint:

eduard

Answer:

Because there is no air resistance

Explanation:

When an object falls on Earth, there are essentially two forces acting on it:

- The force of gravity, downward, equal to the weight of the object:

$W=mg$

where m is the mass and g the acceleration due to gravity

- The air resistance, F, which acts upward, and whose magnitude is generally proportional to v, the speed of the object

When the object starts its fall, its initial speed is zero: v = 0, so the air resistance is also zero: F=0, and the object accelerates downward due to gravity.

However, as it accelerates downward, its speed increases, and so does the air resistance F. However, F is upward, opposite to the direction of motion, therefore it reduces the net acceleration of the object; at a certain point, the magnitude of the air resistance will become equal to the weight, so that

mg = F

and at that point, the net acceleration of the object will become zero: this means that the object will continue its fall at a constant velocity, called terminal velocity.

On the Moon instead, there is no air resistance: this means that for an object falling down, the speed keeps increasing due to the effect of gravity, and it will never reach a terminal value: therefore, the final velocity at the impact will be much higher than on the Earth, if we assume the two objects have been dropped from a very high altitude from the surface.

7 0

3 years ago

Which circuit is a series circuit ?? plz help

gregori [183]

In a series circuit, all of the components are connected in the same 'loop' and the current only has one direction/path it can flow through.

In the first three options, the current has multiple paths it can go through. So these three circuits are parallel and not series.

In the last option, the current only has one path where it can flow through, so that circuit is in series.

So Circuit <u>D </u>is a series circuit.

----------------------------------------

Answer

Circuit D

7 0

3 years ago

Read 2 more answers

Write down any four points that should be considered during household wiring

Shalnov [3]

1. Safety equipment is available
2. Person attempting the task has some general knowledge about wiring
3. Not All Cable is Color-Coded
Cable-sheath color coding started in 2001 and is still voluntary. If you have older wiring, don’t assume it complies with the current color coding. However, most manufacturers now follow the standard color code.
4. Stranded wire is more flexible than solid. If you’re pulling wire through conduit, stranded wire makes it easier to get around corners and bends in the conduit. However, if the situation requires pushing wires through conduit, you’ll want to use solid wire.

8 0

4 years ago

Read 2 more answers

As SCUBA divers go deeper underwater, the pressure from the weight of all the water above them increases tremendously which comp

slavikrds [6]

Answer: A.

As a diver rises, the pressure on their body decreases which allows the volume of the gas to decrease.

Explanation:

The problem is that a diver, experiences an increased pressure of water compresses nitrogen and more of it dissolves into the body. Just as there is a natural nitrogen saturation point at the surface, there are saturation points under water. Those depend on the depth, the type of body tissue involved, and also how long a diver is exposed to the extra pressure. The deeper a diver go, the more nitrogen the body absorbs.

The problem is getting rid of the nitrogen once you ascend again. As the pressure diminishes, nitrogen starts dissolving out of the tissues of the diver's body, a process called "off-gassing." That results in tiny nitrogen bubbles that then get carried to the lungs and breathed out. However, if there is too much nitrogen and/or it is released too quickly, small bubbles can combine to form larger bubbles, and those can do damage to the body, anything from minor discomforts all the way to major problems and even death.

4 0

3 years ago