The answer is B
because if you compare a regular road and ice... ice is smoother and therefore has less friction
Explanation:
Given that,
Electrostatic force,
Distance,
(a) , q is the charge on the ion
(b) Let n is the number of electrons are missing from each ion. It can be calculated as :
n = 2
Hence, this is the required solution.
Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:
Where corresponds to Plank constant (6.626070x10^-34Js), is the speed of light in the vacuum (299792458m/s) and is the wavelength of the photon(in this case 800nm).
Tranform the units
The band Gap is 4eV, divide the band gap between the energy of the photon:
Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.
Answer:
Sarah is right
Explanation:
This is an exercise that differentiates between scalars and vectors.
A scalar is a number, instead a vector is a number that represents the module in addition to direction and sense.
In this case, the distance (scalar) traveled is a number, which is why it is worth 1500m, but the displacement is a vector and since the point where it leaves is the same point where the vector's modulus arrives is zero, so the DISPLACEMENT VECTOR is zero
consequently Sarah is right
Answer:
No sand doesn't stay sand forever.
Explanation:
- We may have a thought that the sand we see on the beach areas are always the same one for eternal, but it is not true.
- Due to different activities like beach nourishment, sand replenishment etc. the sand in the beach areas are changed and replaced.
- If the sand remained there for long time, it also affects the sand eating organisms and plants.