The wave takes 11.3 s to cover a distance of 26.5 m, so its speed is:

The distance between two consecutive crests is 3 m, and this corresponds to the wavelength of the wave. To find its frequency, we can use the relationship between the speed v, the wavelength

and the frequency f:
Answer:
40 cm
Explanation:
We are given that
Load=800 N
Effort=200 N
Load distance=10 cm
We have to find the effort distance.
We know that

Using the formula

Effort distance=
Effort distance=
Effort distance=40 cm
Hence, the effort distance will be 40 cm.
Answer:
Selenium is a semiconductor
Explanation:
Selenium is a semiconductor.
Elements in the column IV and VI of the periodic table are referred to as Semiconductor.
Selenium lies in the column VI along with Tellurium
Some other elements of the column IV are silicon, germanium, and tin
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.
If you mean S is the distance then it is true
Velocity = Distance / time