Answer:
2 charges of electron (2C)
Explanation:
I = Q/t
2 = Q/1
Q = 2×1= 2C
Q = 2 charge of electron
We need to consider for this exercise the concept Drag Force and Torque. The equation of Drag force is

Where,
F_D = Drag Force
= Drag coefficient
A = Area
= Density
V = Velocity
Our values are given by,
(That is proper of a cone-shape)



Part A ) Replacing our values,


Part B ) To find the torque we apply the equation as follow,



Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
Answer:
When you are performing spike it's most effective to strike the ball from the right or left side at a sharp downward angle. Whether you are spiking the ball from the right or left front position, position yourself behind the 10-foot line (attack line), which is the line that is about four steps away from the net.
Answer:
a) 
Now we can replace the velocity for t=1.75 s

For t = 3.0 s we have:

b) 
And we can find the positions for the two times required like this:
And now we can replace and we got:

Explanation:
The particle position is given by:

Part a
In order to find the velocity we need to take the first derivate for the position function like this:

Now we can replace the velocity for t=1.75 s

For t = 3.0 s we have:

Part b
For this case we can find the average velocity with the following formula:

And we can find the positions for the two times required like this:
And now we can replace and we got:
