an independent variable (IV) that you can change. • Typical IV's might be number of fins, length of rocket, type of material, mass of the rocket. • Choose one dependent variable (DV) and make three launches per DV for each IV for a total of. six launches..
Explanation:
Answer:
50km/hr is the velocity of a car that traveled a total of 75 km North in 1.5 hours.
The chair does not move along the vertical direction: this means that the net force on the vertical direction is zero.
There are three forces acting along the vertical direction:
- The weight, acting downward: 
- The component of the force F perpendicular to the floor, acting downward: 
- The normal force N, acting upwards.
Since the net force must be zero, we have:

From which we can find the value of N:

The Atomic Number is equal to the amount of Protons and Electrons. To find the amount of Neutrons in an atom, you have to look at the Mass Number. The Mass Number is the SUM (_+_=_) of Protons and Neutrons in an atom. In this case, you will have to make up equations. For example: Argon. Argon's Mass Number is 40. You need to find the amount of Protons in the atom (18). Mass Number (40) - Protons (18) = Amount of Neutrons. 40-18=22.
Argon has 22 Neutrons, because Protons(18)+Neutrons(22)=Mass Number(40).
Hope I could help!