[O.04H]The table below shows the use of some energy production methods over time. Type of energy Average energy used annually in the past (in million tons) Average energy used annually at present (in million tons) Average energy most likely to be used annually in the future (in million tons)
Oil 200 4000 300
Gas 100 2500 700
Coal 1000 2500 1500
Wind 0.1 50 2000
Hydropower 0.7 60 150
Tidal power 0.02 50 500

Based on the table, which of these statements best describes the impact of different methods of energy production on the environment in the past?
There was a rise in the height of tides.
There was a rise in greenhouse gases.
The coastal ecosystem was harmed.
The coastal areas were highly polluted.

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Which atomic model was proposed as a result of j. j. thomson’s work?