Answer:
Intensity,
Explanation:
Power of the light bulb, P = 40 W
Distance from screen, r = 1.7 m
Let I is the intensity of light incident on the screen. The power acting per unit area is called the intensity of the light. Its formula is given by :
So, the intensity of light is .
Answer:
X-rays travel through space faster than radio waves.
Explanation:
Electromagnetic waves consist of oscillations of the electric and the magnetic field in a plane perpendicular to the direction of motion the wave.
All electromagnetic waves travel in a vacuum always at the same speed, the speed of light, whose value is:
Electromagnetic waves are classified into 7 different types, according to their wavelength/frequency. From shortest to longest wavelength (and so, from highest to lowest frequency), we have:
Gamma rays
X rays
Ultraviolet
Visible light
Infrared radiation
Microwaves
Radio waves
Now we can analyze the 4 statements:
X-rays and radio waves are both forms of light, or electromagnetic radiation --> TRUE. They are both types of electromagnetic waves.
X-rays have higher frequency than radio waves. --> TRUE, as we can see from the table above.
X-rays have shorter wavelengths than radio waves. --> TRUE, as we can see from the table above.
X-rays travel through space faster than radio waves. --> FALSE: all electromagnetic waves travel in space at the same speed, the speed of light.