Answer:
Approximately 0.0898 W/m².
Explanation:
The intensity of light measures the power that the light delivers per unit area.
The source in this question delivers a constant power of
. If the source here is a point source, that
of power will be spread out evenly over a spherical surface that is centered at the point source. In this case, the radius of the surface will be 9.6 meters.
The surface area of a sphere of radius
is equal to
. For the imaginary 9.6-meter sphere here, the surface area will be:
.
That
power is spread out evenly over this 9.6-meter sphere. The power delivered per unit area will be:
.
Longitudinal waves transfer energy parallel to the direction of the wave motion
Answer:
The difference in the length of the bridge is 0.42 m.
Explanation:
Given that,
Length = 1000 m
Winter temperature = 0°C
Summer temperature = 40°C
Coefficient of thermal expansion 
We need to calculate the difference in the length of the bridge
Using formula of the difference in the length

Where,
= temperature difference
=Coefficient of thermal expansion
L= length
Put the value into the formula


Hence, The difference in the length of the bridge is 0.42 m.
Answer:
you use the Ohms law so to find the voltage you would need to multiply the current by the resistance which gives you the power.
V- voltage
I- current
R- resistance
V= I×R