When a person bends an arm a different muscle is used to bring it back to the original position. why can't the same muscle be used to both bend and unbend the arm?

Solid materials that do not possess an orderly arrangement of atoms are called

A U-shaped valley is most often formed by A. volcanoes B. oceans waves C. plate movement D. glacial movement

An object is hanging from a rope. When it is held in air the tension in the rope is 8.86 N, and when it is submerged in water the tension is 7.84 N. What is the density of the the object

What type of wave would michael produce by shaking his finger back and forth twenty-five times per second? a. a longitudinal wave that he could not hear b. a sound wave that he could just barely hear c.

When light hits a smooth, shiny surface, the light A) reflects. B) refracts. C) speeds up. D) diffracts.

Why is it important for engineers to design bumper cars safely

What must her minimum speed be just as she leaves the top of the cliff so that she will miss the ledge at the bottom, which is 1.75 m wide and 9.00 m below the top of the cliff?

Which statement describes how light behaves when it strikes a translucent material? A. Light is scattered. B. Light is transmitted. C. Light is reflected. D. Light is absorbed.

A certain gas is present in a 15.0 l cylinder at 2.0 atm pressure. if the pressure is increased to 4.0 atm the volume of the gas decreases to 7.5 l.

Choose all the answers that apply. To qualify as a planet, a celestial object must: have an irregular shape revolve around the sun orbit in a clear area have enough gravity to have a spherical shape have a satellite