Science is an art, u cant make art without creativity
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
Explanation:
Given formula:
ME=
mv²+mgh
To make height the subject of the formula, follow the following procedures;
Subtract
mv² from both side of equation
M.E -
mv² =
mv² -
mv²+mgh
This gives:
M.E -
mv² = mgh
Multiply both sides of the expression by 
( M.E -
mv² ) x
=
x mgh
h = ( M.E -
mv² ) x 
Learn more:
Kinetic energy brainly.com/question/6536722
#learnwithBrainly
Answer:
Induced emf, 
Explanation:
Given that,
Length of the helicopter, l = 4 m
Angular speed of the helicopter, 
The vertical component of the Earth’s magnetic field is, 
We need to find the induced emf between the tip of a blade and the hub. The induced emf in terms of angular velocity of an rotating object is given by :



So, the induced emf between the tip of a blade and the hub is
. Hence, this is the required solution.