Answer:
If a car skids 66 ft on wet concrete, it will move at 243 ft/s when the brake is applied.
Explanation:
To determine how fast the car was moving, after skidding, the formula below is used:
V = √32*fd
V is the car's speed (ft/s)
d is skid length (ft) = 66 ft
f is the coefficient of friction determined by the material the car was skidding on.
Coefficient of friction for wet concrete is 0.65
V = √32*fd
V = √32 *0.65* 66
V = 242.679 ft/s ≅ 243 ft/s (nearest whole number)
If a car skids 66 ft on wet concrete, it will move at 243 ft/s when the brake is applied.
Newton’s first law is motion. For example, an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
Answer:
A. Geocentric: This model is Earth Centered
. Retrograde motion is explained by epicycles
.
B. Heliocentric: This model is Sun centered. Retrograde motion is explained by the orbital speeds of planets
C. Both geocentric and heliocentric: Epicycles and deferents help explain planetary motion
. Planets move in circular orbits and with uniform motion
. The brightness of a planet increases when the planet is closest to Earth.
Explanation:
The principle of the Ptolemy's geocentric model was developed on the assumption that the center of the universe is the Earth. On the other hand, the principle of the Copernicus' heliocentric model was based on the assumption that the center of the universe is the sun. However, both models have a common ideology on uniform circular motion and epicycles.
Answer:
1.843 x 10^-5 C
Explanation:
<u><em>Givens:
</em></u>
It is given that the air starts ionizing when the electric field in the air exceeds a magnitude of 3 x 10^6 N/C, which means that the max electric field can stand without forming a spark is 3 x 10^6 N/C.
Also it is given that the radius of the disk is 50 cm, it is required to find out the max amount of charge that the disk can hold without forming spark, which means the charge that would produce the max magnitude of the electric field that air can stand without forming spark, and since we know that the electric field in between 2 disk "Capacitor" is given by the following equation
E = (Q/A)/∈o (1)
Where,
Q: total charge on the disk.
A: the area of the disk.
<u><em>Calculations: </em></u>
We want to find the quantity of charge on the disk that would produce an electric field of 3 x 10^6 N/C, knowing the radius of the disk we can find the cross-section of the disk, thus substituting in equation (1) we find the maximum quantity of charge the disk can hold
Q = EA∈o
= (3 x 10^6) x (π*0.50) x (8.85 x 10^-12)
= 1.843 x 10^-5 C
note:
calculations maybe wrong but method is correct
