They both are mechanical waves.
Explanation:
Echolocation and ultrasounds are both mechanical waves that require a medium to trace through. They both process and transfer information through waves; the difference is that we humans cannot hear ultrasound waves.
Answer:
v = 1.98 mph
Explanation:
Given that,
Speed to travel one mile is 100 mph
Speed to travel another mile is 1 mph
The formula used to find your average speed is given by :

Putting the values, we get :

v = 1.98 mph
So, yours average speed is 1.98 mph.
Answer:
The electric flux is zero because charge is zero.
Explanation:
Given that,
Positive charge 
Negative charge 
We need to calculate the total charged
Using formula of charge

Put the value into the formula


We need to calculate the electric flux
Using formula of electric flux

Put the value into the formula

Hence, The electric flux is zero because charge is zero.
Answer:
The work is -67.76 J
Explanation:
The law of conservation of energy is considered one of one of the fundamental laws of physics and states that the total energy of an isolated system remains constant. except when it is transformed into other types of energy.
This is summed up in the principle that energy can neither be created nor destroyed in the universe, only transformed into other forms of energy.
In this case you must calculate the loss of kinetic energy. This loss is actually the work done against the resistive force in the air. Friction is the only force other than gravity that acts on the ball.
So, the loss of kinetic energy is 
You know:
- mass=m=0.22 kg
- Initial velocity of the ball:

Final velocity of the ball: 
Replacing:
= -67.76 J
Friction work is always negative because friction is always against displacement.
<u><em>The work is -67.76 J</em></u>