Hi there!
Initially, we have gravitational potential energy and kinetic energy. If we set the zero-line at H2 (12.0m), then the ball at the second building only has kinetic energy.
We also know there was work done on the ball by air resistance that decreased the ball's total energy.
Let's do a summation using the equations:

Our initial energy consists of both kinetic and potential energy (relative to the final height of the ball)

Our final energy, since we set the zero-line to be at H2, is just kinetic energy.

And:

The work done by air resistance is equal to the difference between the initial energy and the final energy of the soccer ball.
Therefore:

Solving for the work done by air resistance:


Answer:
The acceleration is 2 m/s2.
Explanation:
We calculate the acceleration (a), with the data of mass (m) and force (F), through the formula:
F = m x a ---> a= F/m
a = 40 N/20 kg <em> 1N= 1 kg x m/s2</em>
a= 40 kgx m/s2/ 20 kg
<em>a= 2 m/s2</em>
Answer:
The period of rotation is
T=8.025s
Explanation:
The person is undergoing simple harmonic motion on the wheel
Given data
mass of the person =75kg
Radius of wheel r=16m
Velocity =8.25m/s
The oscillating period of simple harmonic motion is given as
T=(2*pi)/2=2*pi √r/g
Assuming that g=9.81m/s
Substituting our data into the expression we have
T=2*3.142 √ 16/9.81
T=6.284*1.277
T=8.025s
Answer:She would need to first know the weight of the sculpture and what she is going to move it with then she will need to use newton's second law to calculate the amount of force needed to move it
Explanation: I just did the assignment on edgunity
Answer:

Explanation:
Given:
- Three identical charges q.
- Two charges on x - axis separated by distance a about origin
- One on y-axis
- All three charges are vertices
Find:
- Find an expression for the electric field at points on the y-axis above the uppermost charge.
- Show that the working reduces to point charge when y >> a.
Solution
- Take a variable distance y above the top most charge.
- Then compute the distance from charges on the axis to the variable distance y:

- Then compute the angle that Force makes with the y axis:
cos(Q) = sqrt(3)*a / 2*r
- The net force due to two charges on x-axis, the vertical components from these two charges are same and directed above:
F_1,2 = 2*F_x*cos(Q)
- The total net force would be:
F_net = F_1,2 + kq / y^2
- Hence,

- Now for the limit y >>a:

- Insert limit i.e a/y = 0

Hence the Electric Field is off a point charge of magnitude 3q.