Why is coal costly to produce?

1. coal is found deep underground.

2. Coal is expensive to make

3. Coal is only found in certain places on earth.

4. Coal is difficult to make in the lab.

How does Kepler's first law refine the Copernican model?

It takes 40 j to push a large crate 4 m across a floor the force exerted on the crate i

Light takes 1.28 s to travel from the moon to earth. what is the distance between them?

A skier is pulled up a slope at a constant velocity by a tow bar. The slope is inclined at 21.5 ° with respect to the horizontal. The force applied to the skier by the tow bar is parallel to the slope. The skier's mass is 55.

Can angular displacement b both scalar and vector?

A car rounds a 75-m radius curve at a constant speed of 18 m/s. a ball is suspended by a string from the ceiling the car and moves with the car. the angle between the string and the vertical is:

A wave has a wavelength of 7 mm and a frequency of 9 hertz. What is its speed?

Which statement best describes the effect of scientific advances on society? A. They always have a positive impact on society. B. They are inspired by the needs of society. C. they do not affect society beyond the community level. D.

Which is the best example of reusing? repairing a stove instead of buying a new one wearing a pair of pants made from cotton buying a toy packaged in paper instead of plastic placing a glass bottle in the recycling bin

The sunlight hits the surface of a lake this will like caused a. condensation b. transpiration c. evaporation d. sublimation