How can one explain the fact that nearly all other galaxies appear to be moving farther away from us?

a) the universe is expanding b) the apparent motion is just an optical illusion

What is the fundamental property of matter that can either be positive or negative?

The gravitational force on a baseball is 1.4 N. What is its mass? Round to two decimal places.

An older-model car accelerates from 0 to speed v in a time interval of Δt. A newer, more powerful sports car accelerates from 0 to 4v in the same time period.

Carbon-12 Carbon-13 Carbon-14 Which BEST describes the difference between carbon-12 and carbon-14? A. Carbon-12 has one more neutron than carbon-14. B. Carbon-12 has two less protons than carbon-14. C. Carbon-14 has one less proton than carbon-12. D.

Convert 32km/hr to m/s

How do we use light in space?

What units are used for gravitational potential energy? Write the name, not the symbol.

A 7.5 kg block is placed on a table. If it's bottom surface area is 0.6m2, how much pressure does the block exert on the tabletop? A. 376.5 Pa B. 73.5 Pa C. 226.5 Pa D. 122.5 Pa

A boulder of mass 2000 kg is at the top of a cliff of height 220 m. Determine how fast the boulder will be moving when it strikes the dirt below.

Which of the following statements are true? Check all that apply. O A positive charge and a negative charge attract each other. O Electric charge is conserved. O Two positive charges attract each other. O A neutral object contains no charge.