Which statement describes why scientists notation is useful

A 50.6 g ball of copper has a net charge of 1.6 µc. what fraction of the copper's electrons have been removed? (each copper atom has 29 protons, and copper has an atomic mass of 63.5.

Kiley went 5.7 km/h north and went 5.8km/h west. From start to finish, she went 8.1 km/h northwest which best describes her numbers?

Strontium-85 has a half-life of 65 days. how long will it take for the radiation level of strontium-85 to drop to one-fourth of its original level?

Which of the following objects works by burning fuel to push hot air toward the ground and create thrust to use in lifting off? a. rocket c. space station b. space probe d. all of the above

Jenny dissolves as much salt as she can in 100 mL of room-temperature water. She learned in class that less salt will dissolve in cold water than in hot water. Jenny adds some ice to the salt water and observes what happens.

If a cheetah runs at 25 m/s, how long will it take a cheetah to run a 100 m dash?

A gardener pushes her 90 kg wheelbarrow in a straight line out of her garage and across the yard in 18 s. If her average velocity is 1.5 m/s, what is her displacement? A. 0.8 km B. 12 km toward the garden C. 18 m toward the garage D.

What is true about the refractive index of a medium? A. It increases with an increase in angle of incidence. B. It decreases with a decrease in angle of refraction. C. It decreases with an increase in angle of incidence. D.

A car accelerates from rest to 19 m/s in 6 seconds. What is the acceleration of the car?

An apparatus similar to the one used in lab uses an oscillating motor at one end to vibrate a long rope with frequency f = 40 Hz and amplitude A = 0.25 m. The rope is held at constant tension by hanging a mass on the other end.