Answer:
The precise point is that gravitational energy is potential energy unless it makes something move, and then the energy is converted to kinetic energy, no work can be done. So a big rock at the top of a hill has no kinetic energy. Its only when it rolls down that work is done, and this can be converted to useful energy.
Explanation:
Answer: 40
Explanation:
I believe this is correct. I did 60/1.5 to get 40/mph
Answer: 0.25 seconds.
Explanation:
The yo-yo does 240 revolutions in one minute, and we know that one minute has 60 seconds, then the revolutions per second can be calculated as:
240 rev/60s = 4 rev/s, this will be the frequency of the yo-yo
The frequency is actually written as: f = 4 Hz = 4 s^-1
We want to find the period of this yo-yo.
The period is the duration of one cycle, and we have the relation:
f = 1/T
Where f is the frequency and T is the period, then:
T = 1/f
And we know the value of f, it is f = 4 s^-1
Then the period will be:
T = 1/(4 s^-1) = (1/4) s
Then the period of the yo-yo is 1/4 seconds = 0.25 seconds.
Answer:
1.....
2.....
Explanation:
1. For the elements in column 1,2 and 13-18 the atoms in the same column have the same amount of outermost electrons, called valence electrons. Atoms in column 1 (H, Li and Na for example) have 1 valence electron.
2. Electron affinity increases from left to right across the periodic table. This is caused by the decrease in atomic radius. As we already explained, moving from left to right across a period, atoms become smaller and smaller as the atomic number increases.
Answer:
The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.
