What does it mean to say that the forces acting on an object are balanced? a. the forces occur as pairs of forces with equal magnitude and direction. b. all the forces combine to give zero net force. c. the sum of the horizontal forces is zero. d. the forces all have the same magnitude.

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

Question 11 of 13 (1 point) jump to question: a stairway, ladder, or ramp must be present in excavations in which of the following situations? a. all trenches must have access/egress b. the trench is more than 15 feet wide but only 1 ½ feet deep c. the trench is more than 4 feet deep and the devices must be within 25 feet of all workers