A book 15.6 cm tall is 28.7 cm to the left of a plane mirror. What is the height of the image formed?

15.6 cm

13.1 cm

7.76 cm

28.7 cm

Apossible explanation for a set of facts that can be tested by further investigation is called

Where do magnetic lines of force enter earth?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".