Answer:
Distance = 6.667 kilometres
Explanation:
Given the following data;
Speed = 20 km/h
Departure time = 7:00
Arrival time = 7:20
Time taken = 20 minutes
To calculate the distance travelled from home to school;
First of all, we would have to convert the value of time in minutes to hours.
Conversion:
60 minutes = 1 hour
20 minutes = X hours
Cross-multiplying, we have;
X = 20/60 = 1/3 hours
Mathematically, the distance travelled by an object is calculated by using the formula;
Distance = speed * time
Distance = 20 * 1/3
Distance = 20/3 =
Distance = 6.667 kilometres
I don't actually understand what your question is, but I'll dance around the subject
for a while, and hope that you get something out of it.
-- The effect of gravity is: There's a <em>pair</em> of forces, <em>in both directions</em>, between
every two masses.
-- The strength of the force depends on the <em>product</em> of the masses, so it doesn't matter whether there's a big one and a small one, or whether they're nearly equal.
It's the product that counts. Bigger product ==> stronger force, in direct proportion.
-- The strength of the forces also depends on the distance between the objects' centers. More distance => weaker force. Actually, (more distance)² ==> weaker force.
-- The forces are <em>equal in both directions</em>. Your weight on Earth is exactly equal to
the Earth's weight on you. You can prove that. Turn your bathroom scale face down
and stand on it. Now it's measuring the force that attracts the Earth toward you.
If you put a little mirror down under the numbers, you'll see that it's the same as
the force that attracts you toward the Earth when the scale is right-side-up.
-- When you (or a ball) are up on the roof and step off, the force of gravity that pulls
you (or the ball) toward the Earth causes you (or the ball) to accelerate (fall) toward the Earth.
Also, the force that attracts the Earth toward you (or the ball) causes the Earth to accelerate (fall) toward you (or the ball).
The forces are equal. But since the Earth has more mass than you have, you accelerate toward the Earth faster than the Earth accelerates toward you.
-- This works exactly the same for every pair of masses in the universe. Gravity
is everywhere. You can't turn it off, and you can't shield anything from it.
-- Sometimes you'll hear about some mysterious way to "defy gravity". It's not possible to 'defy' gravity, but since we know that it's there, we can work with it.
If we want to move something in the opposite direction from where gravity is pulling it, all we need to do is provide a force in that direction that's stronger than the force of gravity.
I know that sounds complicated, so here are a few examples of how we do it:
-- use arm-muscle force to pick a book UP off the table
-- use leg-muscle force to move your whole body UP the stairs
-- use buoyant force to LIFT a helium balloon or a hot-air balloon
-- use the force of air resistance to LIFT an airplane.
-- The weight of 1 kilogram of mass on or near the Earth is 9.8 newtons. (That's
about 2.205 pounds). The same kilogram of mass has different weights on other planets. Wherever it is, we only know one of the masses ... the kilogram. In order
to figure out what it weighs there, we need to know the mass of the planet, and
the distance between the kilogram and the center of the planet.
I hope I told you something that you were actually looking for.
Answer: 2, the nuclear strong force drops to practically nothing at large distances.
Explanation: The protons and neutrons in the nucleus share subatomic particles called pions. This exchange is what keeps the protons and neutrons stuck together in the nucleus. Despite the strong force being the strongest force, it has a very small range. This is because pions have very short lifespans. So, the strong force would have literally no effect at large distances.
Hope that helped! :)
Answer:
a) truc is C, b) correct result is the B
Explanation:
As the speed of the competition is very high, for the judges the speed is
v = d / t
v = 3 109 m / 20
v = 1.5 108 m / s
This is half the speed of light. For these high speeds we must use the relations of special relativity.
For the time t = to γ
For distance L = Lo / γ
γ = √ (1-v2 / c2)
Own time and distance (to and Lo) corresponds to the observer who is not moving the judges in this case
Let's look for the range value
γ = 1 / √ (1 - (1.5 / 3) 2) = 1 / 0.866 = 1.15
The time t = 20 1.15 = 23 s
The distance L = 3 10 9 /1.15 = 2.60 109 m
From these results we see that time increases and the distance is shorter.
Let's review the claims
A) False. It's the opposite
B) False
C) True. It is according to the result found
D) False.
In the nuclear fusion process, we will also use the special relativity that has a relationship between energy and mass
ΔE = c² Δm
As in the process energy is released, for the law of conservation of the mass of energy to be fulfilled, the total mass of the products, He atom, must be reduced.
Therefore the correct result is the B
The approximate height of the tsunami in Alaska in 1958 is 1720ft