Answer:
Average speed is 60 km/hour
Explanation:
When we need to calculate average speed, we use this equation:
Where: 
position at the beginning
at the end
Then: 
Finally V = 60 km/hour
I believe the correct answer would be kimberlite. Diamonds are usually found in pipes 50 to 200 m across made of kimberlite. It is an igneous rock that is known to contain traces of diamonds. It is named base on the town where it was discovered which is Kimberley, South Africa.
Answer:
Explanation:
Given that
At X=0 V=Vo
At X=X1 V=0
As we know that friction force is always try to oppose the motion of an object. It means that it provide acceleration in the negative direction.
We know that
So the friction force on the box
Ff= m x a
Where m is the mass of the box.
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.
