Answer:
1/3 the distance from the fulcrum
Explanation:
On a balanced seesaw, the torques around the fulcrum calculated on one side and on another side must be equal. This means that:

where
W1 is the weight of the boy
d1 is its distance from the fulcrum
W2 is the weight of his partner
d2 is the distance of the partner from the fulcrum
In this problem, we know that the boy is three times as heavy as his partner, so

If we substitute this into the equation, we find:

and by simplifying:

which means that the boy sits at 1/3 the distance from the fulcrum.
Explanation:
The speed of sound wave only depends on the property of the medium like density and the bulk modulus of the medium particle. The speed of sound also depends on the temperature of the medium.
On comparing sound waves with different frequencies and wavelengths traveling through air, the speed of the wave doesn’t depend on the frequency or the wavelength. Hence, the correct option is (1).
As per Newton's III law every action has equal and opposite reaction
So here we can say that
every body which apply force on other body must have a reaction force of same magnitude in opposite direction
So here if ball hits the ground by 50 N force then the ball must have a reaction force on itself with same magnitude and opposite direction
the magnitude of the force will be 50 N
and its direction is opposite to the force that ball apply on the floor
Depends on how far away the event is and what the temperature is as this affects the speed of sound.
For example, let's say you're 600 meters away and the temperature has no affect.
The speed of sound would be roughly 340 m/s so the time it would take to hear the sound would be 600/340 = 1.76 seconds
The speed of light (c) is 3.0 X 10^8 m/s so the time it would take to see the event would be 600/3 X 10^8 = 2 X 10^-7
Subtract: 1.76 - (2 X 10^-7) = approx. 1.76