Answer:
The answer to this is
6600 Hz to 19,800 Hz
Explanation:
The shape of the human ear is analogous to a closed ended pipe hence
we have λ = 4L or wavelength = 4 * length of the child ear
The frequency c/λ where c = speed of sound = 343 m/s
hence the child's audible range is multiples of 343/(4*0.13) =6600Hz
or 13200 Hz or 19,800 Hz
The generally quoted range of human hearing is 20 Hz to 20 kHz
Answer:
Explanation:
A body under concurrent forces (concurrent forces are forces with their line of action acting at a point) is said to be in equilibrium if the sum total of the forces acting on the body is zero.
For forces acting on a balance, the sum of upward forces and the downward forced acting on the balance must be equal for the balance to be in equilibrium.
Also the sum of clockwise moment must be equal to the sum of anticlockwise moment acting on the balance.
Moment is the product of force and the perpendicular distance from the force to the pivot.
Answer:
= 4.688 106 m
Explanation:
The expression for the center of mass is
R cm = 1 / M ∑ 
Where M is the total mass of the system, ri and m1 are the distance and mass of each particle from a defined origin
Let's look for the total mass, the mass of the moon is m and that of the earth Me
M = 
+ m
M = 81m + m
M = 82 m
The distance from the earth to the moon is R = 384.4 106 m
= 1 / M (M R1 + m R)
= 1 / 82m (0 + m R)
= R / 82
= 384.4 106/82
= 4.688 106 m
The radius of the earth is
= 6371 103 m
= 6.371 106 m
We can see that the center of mass of the system is within the beating radius
