Sound waves travel faster through <em>solids</em> than they do through gases or liquids. <em>(C) </em>They don't travel through vacuum at all.
Example:
Speed of sound in normal air . . . around 340 m/s
Speed of sound in water . . . around 1,480 m/s
Speed of sound in iron . . . around 5,120 m/s
The neutrons are inside the nucleus, have no charge, and have mass.
Answer:
21870.3156 N
Explanation:
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
g = Acceleration due to gravity = 1.6 m/s²
Equation of motion

The acceleration of the craft should be 1.02234 m/s²

Weight of the craft

Thrust

The thrust needed to reduce the velocity to zero at the instant when the craft touches the lunar surface is 21870.3156 N