Great experiment ! Everybody should try it if they can get the equipment.
It demonstrates a lot of things that are very hard to explain in words.
I hope the students remembered to tilt the axis of the globe. If they didn't,
and instead kept it straight up and down, then each city had pretty much
the same amount of bulb-light all the way around, and there were no seasons.
If the axis of the globe was tilted, then City-D had the least variation in
seasons. City-D is only 2° from the equator, so the sun is more direct
there all year around than it is at any of the others.
Answer:
Total kinetic energy of entire system is 3 mgl
Explanation:
Given two masses: m and 4m.
Since the pulley is frictionless and the thread is massless, the energy here is linked to the two masses.
Total kinetic energy of entire system = decrease in gravitational potential energy of the system.
Therefore, we have :
ΔKE = Δp
ΔKE = 4mgl - mgl
= 3 mgl
Total kinetic energy of entire system is 3 mgl
Answer:
19.6m/s
Explanation:
A Rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for certain period of time, for such motion following equation of motion can be used.
here in our case 
because object starts off from rest and 
is acceleration because of gravity ( Motion under gravity).
and of course t = 2 second.
Now by substituting all this information in equation of motion we get.
that would be the velocity of rock as it would hit the ground.
Note! We have assumed that there is no air resistance.
A rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for a certain period of time, for such motion following equation of motion can be used.
here in our case because object starts off from rest and is acceleration because of gravity ( Motion under gravity).
and of course t = 2 seconds.
Now by substituting all this information in equation of motion we get.
V = 19.6m/s
that would be the velocity of rock as it would hit the ground.
Note! We have assumed that there is no air resistance.
Cold.
Example: A frozen object (such as ice) is solid. Its molecules move extremely slow because the object itself isn't moving... It's like the skin on your bod... Imagine that wiggling and writhing on your bones. It's not like a gas, that can move freely and has no specific form or hold.
So again, the answer is Cold.
