The heat (energy) needed to raise the temperature of the water is given by

The wavelength of the radiation of the oven is

, so the energy of a single photon of this radiation is

So, the number of photons required to heat the water is the total energy absorbed by the water divided by the energy of a single photon:

photons
option c...have the waves move thru the vacuum or space
The cyclist accelerates from 0 m/s to 9 m/s in 3 seconds with an acceleration of 3 m/s².
Answer:
Explanation:
Acceleration exerted by an object is the measure of change in speed or velocity of that object with respect to time. So the initial and final velocities play a major role in determining the acceleration of the cyclist. As here the initial velocity of the cyclist is the speed at rest and that is given as 0 m/s. Then after 3 seconds, the velocity of the cyclist changes to 9 m/s.
Then acceleration = change in velocity/Time.

Acceleration = (9-0)/3=9/3=3 m/s².
So the cyclist accelerates from 0 m/s to 9 m/s in 3 seconds with an acceleration of 3 m/s².