A star is moving toward the earth with a speed of 0.9 c (90% the speed of light). it emits light, which moves away from the star at the speed of light. relative to us on earth, the speed of the light moving towards us (emitted by the star) is

Which of the following radioactive emissions is the most penetrating? alpha particles beta particles gamma rays

How is wave velocity calculated?

How are the wavelength and frequency of a wave related? as frequency increases, wavelength increases as frequency increases, wavelength decreases wavelength remains constant as frequency changes wavelength and frequency are not related?

Quasar spectra often show many absorption lines that all appear to be as a result of the same electron transition (such as level 1 to level 2 in hydrogen) but that fall at different wavelengths in the spectrum. Why do we think this is the case?

Two carts with masses of 4.2 kg and 3.2 kg move toward each other on a frictionless track with speeds of 5.4 m/s and 4.5 m/s, respectively. The carts stick together after colliding head-on. Find their final speed. Answer in units of m/s.

Consider a rough asphalt roadway with 17 cm curbs and one 3.75 m lane in each direction and a 1.45 m shoulder on each side. The road has a longitudinal slope of 0.75% and is crowned in the center with a transverse slope of 2.25%.

An example of an opinion would be which of the following? bob s burgers is the best show on television. cake is appropriate for many occasions. earth is 238,900 miles from the moon. none of these

Which is a concern about mining for uranium? -Heated water could be released into the environment. -Dust released in the air could be radioactive. -Supplies could become low during a drought.

In 1986, a gargantuan iceberg broke away from the Ross Ice Shelf in Antarctica. It was approximately a rectangle 160 km long, 40.0 km wide, and 250 m thick. What is the mass of this iceberg, given that the density of ice is 917 kg/m3?

The weight of an astronout is 60kg on earth, find the wight of the same object on the planet where the gravitational attraction has been reduced to 1/10 of the earths pull