A person walks first at a constant speed of 2 m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 4 m/s. What is the average speed (in m/s) over the entire trip? Select one:

a. 2.67

b. 1.33

c. 5.33

d. 2.00

e. zero

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

What are similarities and differences between refraction, reflection, diffraction and absorption?

The period of a pendulum varies directly as the square root of the length of the pendulum and inversely as the square root of the acceleration due to gravity. find the period when the length is 144 cm and the acceleration due to gravity is 980 cm per second squared, if the period is 7pi seconds when the length is 289 cm and the acceleration due to gravity is 980 cm per second squared.