Answer:
Although several scales have been developed over the years, the two commonly used today in the United States are the moment magnitude scale, which measures magnitude (M), or size, and the Modified Mercalli scale, which measures intensity.
Answer:
The girl exerts more pressure.
Explanation:
Pressure can be defined as the force exerted normally or perpendicularly per unit area.
i.e P = F/A
<u>Girls</u>
Area of the heel = 1cm² = 10^(-4) m²
Force = mg = 50 × 10 = 500N
Pressure =


<u>Elephant</u>
<u>Area</u><u> </u><u>=</u><u> </u><u>2</u><u>5</u><u>0</u><u>cm</u><u>²</u><u> </u><u>=</u><u> </u><u>2</u><u>.</u><u>5</u><u> </u><u>x</u><u> </u><u>1</u><u>0</u><u>^</u><u>(</u><u>-</u><u>2</u><u>)</u><u>b</u><u> </u><u>m</u><u>²</u>
<u>Force</u><u> </u><u>=</u><u> </u><u>mg</u><u> </u><u>=</u><u> </u><u>4</u><u>0</u><u>0</u><u>0</u><u>0</u><u>N</u>
<u>Pressure</u><u> </u><u>=</u><u> </u>
<u>
</u>
<u>
</u>
(a) -1620.8 J
The initial kinetic energy of the skateboarder is:

where m is the skateboarder's mass and u his initial speed;
While the final kinetic energy is

where v is his final speed.
So the change in kinetic energy is

According to the work-energy theorem, the change in mechanical energy (kinetic+potential) of the skateboarder is equal to the work done on it:

where
is the work done by the skateboarder on himself
is the work done by friction
is the change in gravitational potential energy
Solving for
,

(b) 2.97 m
The change in potential energy of the skateboarder can be written as

where
m = 55.6 kg is the mass
g = 9.8 m/s^2 is the acceleration of gravity
is the change in vertical height of the skateboarder
Solving for
,

Where the negative sign means the skateboarder has moved downwards. Since we are interested only in the absolute value, the answer is
h = 2.97 m
Answer:
Explanation:
Let the radius of track required be r.
Centripetal force will be provided by frictional force which will be equal to
m v²/ r
Frictional force = mg x μ
So
m v² /r = mg μ
r = v² / μ g =
v = 29 km /h = 8.05 m /s
r =( 8.05 x 8.05 ) /( .32 x 9.8 ) = 20.66 m
<h3><u>Answer;</u></h3>
formed by erosion
River deltas <u>are formed by erosion</u>.
<h3><u>Explanation;</u></h3>
- <em><u>River delta refers to a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water.</u></em>
- In other words <em><u>river deltas are wetlands that form as rivers empty their water and sediment into another body of water, such as an ocean, lake, or another river</u></em>. It occurs when a River is entering a sea, an ocean, lake a reservoir or another river that is incapable of carrying the supplied sediment.
- Therefore,<u> deltas are formed as a result of erosion by water</u> which involves the carrying of sediments down the rivers to the mouth of river where it accumulates.