Answer:
4. It is the force of the road on the tires (an external force) that stops the car.
Explanation:
If there is no friction between the road and the tires, the car won't stop.
You can see this, for example, when there is ice on the road. You can still apply the brakes (internal force), but since there is no friction (external force) the car won't stop.
The force of the brakes on the wheels is not what makes the car stop, it is the friction of the road against still tires that makes it stop.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus. Option A is correct.
<h3>What is nuclear fusion?</h3>
The process by which two or more tiny nuclei unite to generate a bigger nucleus is known as a nuclear fusion reaction.
The more energy it takes to liberate an electron from a smaller atom. This is referred to as binding energy.
As a result, when two little nuclei fuse together, there is more binding energy than when two big nuclei fuse together.
For example, the fusion of two hydrogen atoms produces more energy than the fusion of one helium atom, and surplus energy is expelled into space upon binding.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus.
Hence, option A is correct.
To learn more about nuclear fusion refer to the link;
brainly.com/question/14019172
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<h2>
Its velocity when it crosses the finish line is 117.65 m/s</h2>
Explanation:
We have equation of motion s = ut + 0.5 at²
Initial velocity, u = 0 m/s
Acceleration, a = ?
Time, t = 6.8 s
Displacement, s = 1/4 mi = 400 meters
Substituting
s = ut + 0.5 at²
400 = 0 x 6.8 + 0.5 x a x 6.8²
a = 17.30 m/s²
Now we have equation of motion v = u + at
Initial velocity, u = 0 m/s
Final velocity, v = ?
Time, t = 6.8 s
Acceleration, a = 17.30 m/s²
Substituting
v = u + at
v = 0 + 17.30 x 6.8
v = 117.65 m/s
Its velocity when it crosses the finish line is 117.65 m/s
Earth's protective magnetic bubble, called the magnetosphere, deflects most solar particles, but in the absence of atmospheric layer, Polyethylene is a good shielding material because it has high hydrogen content, and hydrogen atoms are good at absorbing and dispersing radiation.
The Earth’s atmospheres are kept in place by gravity. The air near the ground is pulled on by gravity and compressed by the air higher in the sky. This causes the air near the ground to be denser and creating different layers with different qualities in which are the atmosphere.
Hope that helps ^^