Answer:
The displacement is zero miles
Explanation:
The displacement of an object that moves from point A to point B is defined as

Where d is the displacement of the object. The displacement does not depend on the trajectory of the object. It only depends on the linear distance between the end point and the starting point.
In this case we know that the person walks from home to work and then walks from work to home. Therefore, the total displacement is the linear distance between the point where its journey begins and the point where the route ends.
The tour begins on the front porch of your house and ends on the front porch of your house (when you return from work). If we call A to the front porch of the house then the displacement is:

The displacement is zero miles, since the person finishes the journey just where it started (front porch)
They can be described as small in quantity and very dangerously radioactive.
Answer: False
Explanation:
Relative to the concept of radiations, a black body is an object capable of absorbing any form of electromagnetic radiation irrespective of its frequency or angle of incidence when incident on such object.
However, the same cannot be said about real bodies as real bodies are those which reflect all rays incident on them completely and uniformly in all directions.
One very important characteristic of black bodies is that they are ideal emmiters.
The concept of emmisivity is brought about by the existence of real bodies .
This is due to the fact that they are only able to emit radiation at a fraction of the black body energy levels.
Please note that by convention, the emmisivity of a real body is always less thaan 1.
As such they are not able to emit as much radiation as a black body at the same temperature.
Answer:
10.58 ft
Explanation:
Force, F = 1.4 N
Diameter of membrane = 7.4 mm
radius of membrane, r = 7.4 / 2 = 3.7 mm = 3.7 x 10^-3 m
Area, A = 3.14 x (3.7 x 10^-3)^2 = 4.3 x 10^-5 m^2
Density, d = 1.03 x 10^3 kg/m^3
Pressure at depth, P = h x d x g
Let h be the depth.
Pressure = force / Area
h x 1.03 x 10^3 x 9.8 = 1.4 / (4.3 x 10^-5)
h = 3.225 m = 10.58 ft
Thus, the depth of water is 10.58 ft.