Answer:
Correct answer letter b.
Explanation:
When the book is on the top shelf of the bookcase, it just only gravitational potential energy, due to the gravitational field and the kinetic energy at this point is zero because the book is at rest.
Now, when the book starts falling, all the potential energy will transform into the kinetic energy. It happens, thanks to the conservation of the energy,that says energy can neither be created nor destroyed, energy can only be transferred or changed from one form to another.
Let's recall that the gravitational potential energy depends on the object's position, so when the book falls, the magnitude of the position decreases and the speed of this object increases.
Therefore, the potential energy of the book decreases as kinetic energy increases.
Correct answer letter b.
I hope it helps you!
Answer:
true
Explanation:
the sun warms the atmosphere and warms the air which drives our weather
Answer:
The value of the average convection coefficient is 20 W/Km².
Explanation:
Given that,
For first object,
Characteristic length = 0.5 m
Surface temperature = 400 K
Atmospheric temperature = 300 K
Velocity = 25 m/s
Air velocity = 5 m/s
Characteristic length of second object = 2.5 m
We have same shape and density of both objects so the reynold number will be same,
We need to calculate the value of the average convection coefficient
Using formula of reynold number for both objects
Here, 
Put the value into the formula
Hence, The value of the average convection coefficient is 20 W/Km².
Answer:
Explanation:
1. cools quickly on the earth's surface
Extrusive igneous rock
2. cools slowly beneath the earth's surface
Intrusive igneous rock
3. formed from the remains of living organisms
Organic sedimentary rocks
4. formed from pieces of other rocks cemented together
Clastic sedimentary rock
5. formed when dissolved minerals harden
Chemical sedimentary rock
6. formed from heat and pressure
Metamorphic rocks
A solenoid hope this is right
