Answer:
B
Explanation:
Newton’s Second Law of Motion
Newton’s Second Law of Motion states that ‘when an object is acted on by an outside force, the mass of the object equals the strength of the force times the resulting acceleration’.
This can be demonstrated dropping a rock or and tissue at the same time from a ladder. They fall at an equal rate—their acceleration is constant due to the force of gravity acting on them.
The rock's impact will be a much greater force when it hits the ground, because of its greater mass. If you drop the two objects into a dish of water, you can see how different the force of impact for each object was, based on the splash made in the water by each one.
Answer:

The formula for escape velocity where:
G - Gravitational constant (9.81 etc.)
M - the mass of the object the escape should be made from
r - distance to the centre of that mass
Diffraction means spreading out of waves that has the same wavelength as the size of the gap. Sound waves have high wavelength and so it diffracts\spreads out and enables anyone to hear your voice from anywhere outside the room.
For inside the room, the sound waves doesn't actually diffract. They collide with the air particles, causing a series of compressions and rarefactions which spreads out in the air particles and anyone can hear your voice.
Air is the medium for the sound waves to travel.