PHYSICS 1: 1D Kinematics Kalamazoo Valley Community College Phy 112 • Kinematics is a way of tracking the motion of an object. • There are five variables for a direction used for most kinematic equations. • Three variables are required to solve any problem. • Use a table to organize your information. X-direction Δ𝑥 ax V0x Vfx time y-direction Δ𝑦 ay V0y vfy time 1D Example A car starts from rest and accelerates to a speed of 18.0m/s in 50.0m. Solve for the time taken and the acceleration of the car. • The solution starts by finding key information in the problem statement. • Look for keywords containing important information. • Make a table to fill in known variables. 1D Example Continued A car starts from rest and accelerates to a speed of 18.0m/s in 50.0m. Solve for the time taken and the acceleration of the car. X-direction Δ𝑥 50.0m ax ??? V0x 0 Vfy 18.0m/s time ??? 1D Example Three variables are required to solve for the others. There is an exception to this that will be covered later. We need to pick an equation that can solve for one of the missing varibles. X-direction Δ𝑥 50.0m ax ??? V0x 0 Vfx 18.0m/s time ??? Δ𝑑 = 𝑣0 ∙ 𝑡 + 12∙a ∙ 𝑡 2 𝑣𝑓 = 𝑣0 + a ∙ 𝑡 𝑣𝑓2 = 𝑣02 + 2 ∙ a ∙ Δ𝑑 𝑣𝑓2 = 𝑣02 + 2 ∙ a ∙ Δ𝑥 1D Example 2 2 + 2 ∙ a ∙ 50𝑚 18𝑚 = 0 𝑠 𝑚2 324 𝑠2 X-direction Δ𝑥 50.0m ax ??? V0x 0 Vfx 18.0m/s time ??? Δ𝑥 = 𝑣0 ∙ 𝑡 + 12∙a ∙ 𝑡 2 𝑣𝑓 = 𝑣0 + a ∙ 𝑡 𝑣𝑓2 = 𝑣02 + 2 ∙ a ∙ Δ𝑥 100𝑚 = 02 a ∙ 100𝑚 + 100𝑚 𝑎 = 3.24𝑠𝑚2 Δ𝑥 = 𝑣0 ∙ 𝑡 + 12∙a ∙ 𝑡 2 50𝑚 = 0 ∙ 𝑡 + 12∙3.24𝑠𝑚2 ∙ 𝑡 2 50𝑚 = 0 ∙ 𝑡 + 1.62𝑠𝑚2 ∙ 𝑡 2 𝑡=± 50𝑚 𝑚 1.62 2 𝑠 𝑡 = +5.56s