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:
Frictional force, F = 45.9 N
Explanation:
It is given that,
Weight of the box, W = 150 N
Acceleration, 
The coefficient of static friction between the box and the wagon's surface is 0.6 and the coefficient of kinetic friction is 0.4.
It is mentioned that the box does not move relative to the wagon. The force of friction is equal to the applied force. Let a is the acceleration. So,
Frictional force is given by :
F = 45.9 N
So, the friction force on this box is closest to 45.9 N. Hence, this is the required solution.
Answer:
They conduct thermal energy from inside the house and release it outside the house. ... It reduces the amount of thermal energy that is transferred from outside to inside the container
The economy will never be fully employed in the future the economy will be completely unemployed because pretty soon we will invent robots that'll take our jobs
Answer:
B. -900 kg-m/s2
Explanation:
First of all, we need to calculate the acceleration of the hockey player, which is given by:
where
v = 12 m/s is the final speed
u = 18 m/s is the initial speed
t = 0.6 s is the time
Substituting into the formula, we find
And now we can calculate the force exerted by using Newton's second law:
where m=90 kg is the mass of the hockey player. Substituting into the formula, we find
