Answer:
A
Explanation: A is a example of Air resistance force, which is a contact force.
Answer:
When an electron is hit by a photon of light, it absorbs the quanta of energy the photon was carrying and moves to a higher energy state. One way of thinking about this higher energy state is to imagine that the electron is now moving faster, (it has just been "hit" by a rapidly moving photon)
A photon is a quantum of EM radiation. Its energy is given by E = hf and is related to the frequency f and wavelength λ of the radiation by. E=hf=hcλ(energy of a photon) E = h f = h c λ (energy of a photon) , where E is the energy of a single photon and c is the speed of light.
The answer is, "B", "Ammonia".
Answer:
Approximately
.
Explanation:
Since the result needs to be accurate to three significant figures, keep at least four significant figures in the calculations.
Look up the Rydberg constant for hydrogen:
.
Look up the speed of light in vacuum:
.
Look up Planck's constant:
.
Apply the Rydberg formula to find the wavelength
(in vacuum) of the photon in question:
.
The frequency of that photon would be:
.
Combine this expression with the Rydberg formula to find the frequency of this photon:
.
Apply the Einstein-Planck equation to find the energy of this photon:
.
(Rounded to three significant figures.)
A. A stretched catapult can do work when released so it must have potential energy.
b. A stone on the ground will not move on its own ever again so it has zero energy.
c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)
d. To lift a stone you must overcome the weight which is the force due to gravity.
e. Work and energy are both measured in Joules.