What gives you a frame of reference for your speed when you are riding a train

a. the wheels of the train

b. the sky overhead

c. the train tracks

d. the station

Compared to yellow light, orange light has A. the same frequency. B. a faster wave velocity. C. a longer wavelength. D. a different polarization.

you can move heavy boxes by sliding them over the ground. Or you can put them on a dolly, and them roll them over the ground

The current in a single-loop circuit with one resistance R is 6.3 A. When an additional resistance of 3.4 Ω is inserted in series with R, the current drops to 4.72 A. What is R?

An ecosystem is all the populations of organisms that live together and A. the microorganisms that depend on them. B. the organisms that generate energy from sunlight. C. the physical factors with which they interact. D.

3. What can you infer about an ion that has a positive charge?

Two water manometers are connected to a tank of air. One leg of the manometer is open to 100kPa pressure (absolute) while the other leg is subjected to 90kPa. Find the difference in deflection between both manometers, Delta h_a - Delta h_b.

Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth, throwing up so much dust that the sun was blocked out for a period of many months. A.

If you drop a silver dollar off a building and it hits the ground in 10 seconds, how fast was the coin going just before it hit?

What is the weight of an with a mass of 32kg

The index of refraction of silicate flint glass for red light is 1.620 and for violet light is 1.660. A beam of white light in this glass strikes the glass-air interface at a 25.50∘ angle of incidence and refracts out into the air.