Answer:
Work done, W = 1786.17J
Explanation:
The question says "A 75.0-kg painter climbs a 2.75-m ladder that is leaning against a vertical wall. The ladder makes an angle of 30.0 ° with the wall. How much work (in Joules) does gravity do on the painter? "
Mass of a painter, m = 75 kg
He climbs 2.75-m ladder that is leaning against a vertical wall.
The ladder makes an angle of 30 degrees with the wall.
We need to find the work done by the gravity on the painter.
The angle between the weight of the painter and the displacement is :
θ = 180 - 30
= 150°
The work done by the gravity is given by :
Hence, the required work done is 1786.17 J.
Answer:
thats a lot, which one u want me to do?
Explanation:
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.
Here's the tool you need. You can't answer the question without this:
"1 watt"
means
"1 joule of energy, generated, used, or moved, every second".
So 60 watts = 60 joules per second
Total energy generated,
used, or moved = (power) x (time).
580 joules = (60 watts) x (time)
Divide each side
by (60 watts): Time = (580 joules) / (60 joules/sec)
= (9 and 2/3) seconds .
