Answer:
At the top of the hill.
Explanation:
As the roller coaster goes up the hill, kinetic energy (K.E) decreases, gravitational potential energy (G.P.E) increases .
As it reach the top of the hill, K.E becomes zero and G.P.E reaches <em>m</em><em>a</em><em>x</em><em>i</em><em>m</em><em>u</em><em>m</em> .
As it goes down the hill, K.E starts to increase and G.P.E decrease .
At the bottom of the hill, K.E reaches <em>maximum</em> and G.P.E becomes zero .
(Correct me it I am wrong)
(0.5)×(0squared)×(3)=(1.5j)
Answer:
The system's potential energy is -147 J.
Explanation:
Given that,
Energy = 147 J
We know that,
System is isolated and it is free from external forces.
So, the work done by the external forces on the system should be equal to zero.

We need to calculate the system's potential energy
Using thermodynamics first equation

Put the value into the formula


Hence, The system's potential energy is -147 J.
The potential energy of the box when it gets to the top is
(mass) (gravity) (height)
= (7 kg) (9.8 m/s²) (5 m)
= 343 joules.
That's the work done against the force of gravity. Any
additional work is done against the force of friction.
Answer:
approximately 304358
Explanation:
wavelength = speed / frequency
speed of an electromagnetic wave is 299,792,458 m/s in a vacuum