Answer: 21965.517 Pa
Explanation:
Pressure 
is the force 
exerted by a gas, a liquid or a solid on a surface (or area) 
, its unit is Pascal 
which is equal to 
and its formula is:
(1)
In this case we have the surface of a sole of a tennis shoe:
(2)
And the mass 
of the person who wears it:
On the other hand, we know the weight is the force the Earth exerts on people and objects due gravity 
:
(3)
Substituting (2) and (3) in (1):
(4)
Finally:
This is the pressure the shoe exert on the ground
Answer:
C. The wheel with spokes has about twice the KE.
Explanation:
Given that
Mass , radius and the angular speed for both the wheels are same.
radius = r
Mass = m
Angular speed = ω
The angular kinetic energy KE given as
I=Moment of inertia for wheels
Wheel made of spokes
I₁ = m r²
Wheel like a disk
I₂ = 0.5 m r²
Now by comparing kinetic energy
KE₁= 2 KE₂
Therefore answer is C.
Answer:
259 Hz or 269 Hz
Explanation:
Beat: This is the phenomenon obtained when two notes of nearly equal frequency are sounded together. The S.I unit of beat is Hertz (Hz).
From the question,
Beat = f₂-f₁................ Equation 1
Note: The frequency of the other instrument is either f₁ or f₂.
If the unknown instrument's frequency is f₁,
Then,
f₁ = f₂-beat............ equation 2
Given: f₂ = 264 Hz, Beat = 5 Hz
Substitute into equation 2
f₁ = 264-5
f₁ = 259 Hz.
But if the unknown frequency is f₂,
Then,
f₂ = f₁+Beat................. Equation 3
f₂ = 264+5
f₂ = 269 Hz.
Hence the beat could be 259 Hz or 269 Hz
