phys111 lesson 2-

1. What is the definition of acceleration?

Acceleration is the rate of change of velocity. In other words, acceleration is the value by which velocity will change each second.

The absolute value of the area under a velocity-time graph is equal to which of the following?

Distance

consider an object that is moving backwards while slowing. Velocity vs. time graph

Since the object moves backwards, the initial velocity will be negative. The object slows which means that the velocity will become closer to zero velocity.

A student examines a velocity vs. time graph. How can the student determine the acceleration of the object?

The acceleration can be found by solving for the slope of the line.

A student examines a velocity vs. time graph. How can the student determine the displacement?

The displacement can be determined by adding up all the areas between the graph line and horizontal axis (keep the negative sign if the area is negative).

A student examines a velocity vs. time graph. How can the student determine the distance?

The distance can be found by adding up all the absolute values of all the areas between the graph line and the horizontal axis.

The object is moving forward while slowing down? The velocity vs. time graph is as follows

The object starts with some positive velocity, which decreases and approaches zero velocity.

Consider an object that is moving backwards while slowing. What will values represent

The slope on the position graph will be negative but decreasing in value as the object slows.

consider an object that starts from rest and then moves backward while speeding up. V vs. time graph The velocity starts at zero, and the velocity values are negative and increasing.

The velocity starts at zero, and the velocity values are negative and increasing. Remember that a negative velocity means backwards motion

Which of the following correctly describes an object moving with constant velocity motion? a) The object travels the same distance each second. b) The object travels with an increasing amount of distance each second. c) The object travels with a decreasing amount of distance each second. d) None of the above.

a) The object travels the same distance each second.

acceleration is a change in?

acceleration is a change in either speed or direction, or both

Area=

base x height + 1/2 base x height

What would you expect a position vs. time graph to look like for an object that is moving forwards while slowing down?

he object is still moving forwards indicating that the slope will be positive. However, the object is slowing down, which means that the slope should become less steep as time progresses.

How are velocity and time related?

linearly

Instantaneous acceleration a

or the acceleration at a specific instant in time, is obtained by the same process as discussed for instantaneous velocity in Time, Velocity, and Speed

1. List the three kinematic equations below. Indicate what variable each of the symbols in the equations represent and the units commonly associated with the variable.

v = at + vo x = ½ at2 + vot + xo v2 = 2a(x-xo) + vo2 v = final velocity (m/s) a = acceleration (m/s/s) vo = initial velocity (m/s) t = time (s) x = final position (m) xo = initial position (m)