Prototype
Chemistry
Technology
Troubleshooting
Hypothesis?
Observing
Variable
Hypothesis?
Engineer
System
Answer:
By conservation of energy, it can climb up to a height equal to that it went down before. However, due to the friction in the machines, the total mechanical energy of the roller coaster will decrease. As a result, the first "hill" of many roller coasters are the highest, but the followings will have decreasing heights.
Explanation:
Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8 
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0 
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2 
Answer:
A
Explanation:
When friction slows a sliding block, <u>the kinetic energy of the block is transformed into internal energy
.</u>
<em>The frictional movement of two surfaces over one another leads to the conversion of some of their kinetic energies to another energy - heat or thermal energy. Hence, the temperatures of the objects are raised in the process. </em>
<u>Therefore, when a sliding block is slowed down due to friction, some of the kinetic energy of the block would be transformed into internal energy in the form of heat.</u>
The correct option is A.
The answer is binary star system