If you hold a 50 kilogram barbell above your head for 3 seconds and

the acceleration due to gravity is 9.8 meters per second per second, how

much work did you do?

OA) OJ

OB) 150 kg s

OC) 490 N

OD 1,470 NS

What is the name of the line drawn perpendicular to the surface where a light ray strikes? a. incoming ray c. normal b. reflected ray d. vertical

Wave C has an amplitude of 1 and wave D has an amplitude of 3 as shown below. What will happen when the trough of wave C meets the crest of wave D?

Convection currents on the Earth are created by the moon and wind energy A. True B. False

What is the average velocity of a dragster that starts from rest at the starting line and finishes a race at 2600 m/s in 12 seconds?

Radiation with a wavelength of 238 nm shines on a metal surface and ejects electrons that have a maximum speedof 3.75 X 105 m/s. Which one of the followingmetal is it, the calues in paretheses being the work functions: a) potassium (2.

In what ways does a river carry its load?

What is a unit of mass?

Which is not an era of the Phanerozoic eon

Newton's third law states that when an object exerts a force on another object, the second object exerts an equal but opposite force on the first object. Which of the following shows an example of this? a.

A car is moving 14.4 m/s when it hits the brakes. It slow from 78.8 m, which take 9.92s. It then accelerates at 1.83 m/s 2 for 4.50 s. What is the total displacement?