Answer:
Mass and velocity.
Explanation:
Kinetic energy <u>is the energy that an object has due to its movement</u>, mathematically it is represented as follows:

where
is the mass of the object, and
is its velocity at a given point in time.
So we can see that to find the kinetic energy just before the ball hits the gound, we need the quantities:
- mass of the ball
- velocity of the ball before it hits the ground
With the knowledge of these two quantities the kinetic energy of the ball before touching the gound can be determined.
I think it is c I'm only in 7th grade but I'm pretty sure that the answer is c
Answer:
8.1 x 10^13 electrons passed through the accelerator over 1.8 hours.
Explanation:
The total charge accumulated in 1.8 hours will be:
Total Charge = I x t = (-2.0 nC/s)(1.8 hrs)(3600 s/ 1 hr)
Total Charge = - 12960 nC = - 12.96 x 10^(-6) C
Since, the charge on one electron is e = - 1.6 x 10^(-19) C
Therefore, no. of electrons will be:
No. of electrons = Total Charge/Charge on one electron
No. of electrons = [- 12.96 x 10^(-6) C]/[- 1.6 x 10^(-19) C]
<u>No. of electrons = 8.1 x 10^13 electrons</u>
Experiments and investigations must be B. Repeatable.
Answer:
3.1 miles
Explanation:
To solve this question it is important to remember that the distance between two mile markers is approximately 1 mile
Once this is known, the question becomes very easy to solve. We make two triangle, which have the following three points
Triangle 1: Hot-Air-Balloon, Ground, Milepost 1 - With angle of depression 20
Triangle 2: Hot-Air-Balloon, Ground, Milepost 2 - With angle of depression 18
As a reminder, the angle of depression is simply the angle the balloonist's head makes with the horizontal plane to be able to see the milepost.
From this we can simply drive two formulas using the Tan function
Equation 1 - 
Equation 2 - 
Solving them simultaneously we get the value of height (h) to be 3.0852 miles or 3.1 miles