The velocity of a ball changes from ‹ 9, −6, 0 › m/s to ‹ 8.96, −6.12, 0 › m/s in 0.02 s, due to the gravitational attraction of the Earth and to air resistance. The mass of the ball is 120 grams.

(a) What is the acceleration of the ball? a with arrow = Correct: Your answer is correct. (m/s)/s

(b) What is the rate of change of momentum of the ball? dp with arrow/dt = Incorrect: Your answer is incorrect. (kg · m/s)/s

(c) What is the net force acting on the ball? F with arrownet = N

Aforce of 34.5 newtons is applied to an object at an angle of 45 º with the horizontal. what is the force acting on the object in the horizontal direction?

A26 cm object is 18 cm in front of a plane mirror. a ray of light strikes the object and is reflected off the mirror at a 42-degree angle. what is the angle of reflection? degrees what type of image is formed? what is the size of the image? cm

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.