Explanation:
Using kinematics,
t = 4s
u = 0m/s
a = 9.8m/s^2
Therefore v = u + at = 0 + (4)(9.8) = 39.2m/s.
In most cases the temperature must increase for thermal expansion to occur. Most substances expand as temperature increases because the atoms or molecules vibrate faster as temperature increases and experience greater separation.
Answer:
Option(a) is the correct answer to the given question .
Explanation:
The main objective of the angular momentum is evaluating however much the rotational movement as well as the angular velocity in the entity does have.The angular momentum is measured in terms of .
- In the given question the skateboarder rides quickly up the bottom of a bowl-shaped surface and climb into the air.it means it is rotational movement also it is not touching anything so it is angular momentum.
- All the other option is incorrect because it is not follows the given scenario
Answer:
Because the mass of electrons and protons is very small
Explanation:
The gravitational force exerted between two objects is given by:
where
is the gravitational constant
m1 and m2 are the masses of the two objects
r is the distance between the two objects
The mass of a proton and of an electron is very small, so the gravitational force involved in case of such particles is very weak. Let's calculate for example the gravitational attraction between one proton and one electron at a distance of r = 1 m. We have:
- Proton mass:
- Electron mass:
So, the gravitational force between the two particles is:
Which is a very weak force.
By comparison, let's calculate instead the electromagnetic force between a proton and an electron (both having a charge of ) still separated by a distance of r = 1 m. We have:
Which we see is much stronger than the gravitational force (almost by a factor