Uniform Acceleration

1. Compare and contrast the Aristotelian and Galilean conceptions of vertical motion, horizontal motion, and projectile motion.

2. Explain how Galileo inferred that objects in a vacuum fall with uniform acceleration, and that force is not necessary to sustain horizontal motion.

​The graph of velocity versus time must be a horizontal line. The displacement may be obtained by computing the area bounded by the horizontal line and the time axis.

Displacement versus time

​How is velocity obtained using the displacement-versus-time graph?

VELOCITY-VERSUS-TIME GRAPH FOR UNIFORMLY ACCELERATED MOTION WITH AN INITIAL VELOCITY V₀

​There are times that the slope (and therefore acceleration), is negative. What does a negative slope mean?

Negative Slope

The graph below is a velocity-time graph of a student as he walks from his dormitory to his school. Describe the type of motion for intervals A-B,

B-C, and C-D. How far is the school from the dormitory?

Solution:

A-B is uniformly accelerated motion

Α_triangle=1/2(base)(height) Α_rectangle=(length)(width)

Therefore,

d_T=d_a-b+d_c-d

_dA-B=1/2(4.0m/s)(20.0s)=40.0m

d_C-D=1/2(4.0m/s)(60.0s)=120.0 m

dT=40.0m+320.0m+120.0m=480.0m

​Performance Task's:

1. How can the motion of an object be observed, described, and measured?

2. How do you describe your day to day motion?

3. How can I make sure of Newton's Law of motion to my advantage?

4. Why are the conservation laws in physic's important?