Who were major innovators of the late nineteenth or early twentieth century?

Choose all answers that are correct.

Alexander Graham Bell

Thomas Edison

Robert Fulton

Orville and Wilbur Wright

Samuel Gompers

Henry Ford

What is the focal length of a concave mirror that magnifies, by a factor of + 3.2 an object that is placed 30 cm from the mirror?

Which explanation best describes the development of a wave?

A lightbulb glows brightly when it is connected across a certain battery. The battery will maintain a constant potential difference even as its output current increases.

A 0.8 m length of wire is formed into a single turn, square loop in which there is a current of 12 A. The loop is placed in magnetic field of 0.12 T, which is perpendicular to a normal to the loop plane.

A football kicker kicks a ball with a mass of. 42 kg. The average acceleration of the football was 14.8 m/s squared. How much force did the kicker supply to the football?

What is the energy source that heats a contracting protostar?

What unit is kg divided by m/s^2

If the energy stored in the fully charged battery is used to lift the battery with 100-percent efficiency, what height is attained? Assume that the acceleration due to gravity is 9.8 m/s2m/s2 and is constant with height

How does the mass of an astronaut change when she travels from earth to the moon? how does her weight change?

If an object has a mass of 20 grams and a volume of 40 cm3, what is its density in g/cm3?