# xt for constant acceleration vt for constant acceleration

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x(t) for constant acceleration

v(t) for constant acceleration

Average velocity therefore

4 equations to use for constant acceleration phenomena (only)

4 equations to use for constant acceleration phenomena (only) Variables: x x 0 v v 0 a t If you know 4 (or sometimes 3) variables, you can solve for the other variables.

Constant Acceleration (Problem Solving) 1. Identify the “main idea” of the problem if it is readily apparent. For example, “constant acceleration. ” 2. Draw pictures, label objects, write knowns and unknowns. Use subscripts with variables if there are multiple objects in the problem. 3. Write physics equations, definitions, and laws that might help solve the problem. 4. Do the math. 5. Check your work. Does the answer make sense?

Example A softball player is running at full speed toward second base with a speed of 12 m/s. She slides for 1. 5 m into second base. Assuming constant acceleration, (1) how much time elapses as she is sliding; and (2) What is her acceleration?

Example Motorcycles have amazing acceleration. The Kawasaki Ninja ZX-14 can reportedly accelerate from 0 to 60 mph in 2. 5 s. What is its acceleration and how far does it travel during this time interval?

Free-fall An “free” object rising or falling near Earth, with negligible air resistance, is a special case of motion with constant acceleration. +y (m)