It starts or speeds up.
Some substances need certain amount of energy in order to react with each other.
Answer:
ANSWERS ARE 100 % correct
Explanation:
trust me
Answer:
I would say that I agree with the one that said that each hill must be lower than the previous one and use the principle of conservation of energy to explain.
Explanation:
Roller coaster are usually designed such that its total energy remains conserved at any point on the track. Now, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. At certain height on the track, the total energy of the roller coaster is in form of potential energy, which gets converted to kinetic energy as soon as it starts sliding down the hill till get to the hill's endpoint where it has maximum kinetic energy. The cycle of sliding from a high point on the track to a low point on the track means there is potential energy is converted to kinetic energy and kinetic energy then converts back to potential energy and the cycle continues.
However, due to the effect of gravity and frictional force between the track and the coaster, the energy of the coaster is gradually reduces, so it becomes a bit difficult for the coaster to move to the next hill of the same height. It is for this reason that each hill must be lower than the previous one, so that the coaster can overcome the next hill's height with its reduced energy until it loses all its energy and comes to a stop.
Answer:
0.4 g/cm^3
Explanation:
The density of an object can be found using the following formula.
d= m/v
where m is the mass and v is the volume.
The mass of the metal is 6 grams and the volume is 15 centimeters^3
m=6 g
v= 15 cm^3
Substitute these into the formula.
d= 6 g/ 15 cm^3
Divide 6 g by 15 cm^3 (6/15=0.4)
d= 0.4 g/ cm^3
The density of the metal is 0.4 grams per cubic centimeter.
Answers:
kinetic energy lost = 86.4J
Explanation:
let Kf be the kinetic energy after the collision and Ki be the kinetic energy before the collision. let the 3kg car be 1 and 2kg car be 2.
Kf = K1(f) + K2(f)
Ki = K1(i) + k2(i)
loss in kinetic energy = Kf - Ki
= 1/2(3)(2.20)^2 + 1/2(2)(2.20)^2 - 1/2(3)(7)^2 - 1/2(2)(-5)^2
= 12.1 - 98.5
= -86.4 J
therefore, the kinetic energy lost in the collision is 86.4 J.