Which of the following systems is not true about machines?

Sometimes a person cannot clearly see objects close up or far away. To correct this type of vision, bifocals are often used.

Which sport is considered both an aerobic and an anaerobic activity?

Which statements about eclipses are true? Check all that apply. Earth's shadow creates a solar eclipse. A total lunar eclipse has a reddish color. The moon moves between Earth and the Sun during a solar eclipse.

Mechanical waves are classified according to

A car traveling at 45 m/s can brake to a stop within 10m. Assume that the braking force is effective for stop and constant with speed.

Which solid is the best thermal insulator A. brass b. ice C. styrofoam D. copper

When a high-mass star explodes, which of the following is left over in the center? A. Black hole B. Neutron star C. White Dwarf D. either a or b

Which object is an insulator?

Whats the difference between population density and population size?

A standing wave is established in an organ pipe that is closed at one end. What is located at the open and closed ends of the pipe?