Answer: 628.31 miles/h
Explanation:
The equation to calculate the average speed 
of an object moving in a circular path is:
(1)
Where:
is the radius of the circumference
is the period, which has an inverse relation with the frequency 
. Then 
Solving the equation:
(2)
(3)
Answer:
It is because the room is occupied with stuffs.
Explanation:
In a well furnished room there are things
like bed, cupboard, wardrobe and other stuffs, So they act as absorbing materials.
They absorb sound and do not give a chance to resounds.
Answer:
Volume, 
Explanation:
Given that,
The diameter of a human cell is 11 μm
It is enclosed by a membrane that is 4,4 nm thick.
We need to find the volume of the cell. The cell is spherical in shape. The volume of a sphere is given by the formula as follows :
r is the radius of the sphere, r = 5.5 μm
So,
So, the volume of the cell is 
.
Answer:
2.01
Explanation:
First, we need to find the centripetal acceleration.
We're given that the merry go round rotates 1 revolution in 2.09 seconds. Converting to rpm, we know that it rotates 30 revolution per minute
Now this speed gotten in rpm will be converted to m/s, to ease the calculation
30 rpm = πdN/60 m/s
30 rpm = (3.142 * 4 * 30)/60
30 rpm = 377.04/60
30 rpm = 6.284 m/s
a(c) = v²/r
a(c) = 6.284²/2
a(c) = 39.49 / 2
a(c) = 19.74 m/s²
F = ma
F = 50 * 19.74
F = 987 N
Also, Normal Force, F(n) =
F(n) = mg
F(n) = 50 * 9.81
F(n) = 490.5
We then use this to find the coefficient of static friction, μ
μ = F/F(n)
μ = 987 / 490.5
μ = 2.01
