Presentation on theme: "Acceleration is the rate of change In velocity."— Presentation transcript:
Acceleration is the rate of change In velocity
vivi aMotion ++Speeding up -- +-Slowing down -+ + or -0Constant 0- Or +Speeding up from rest 00Remaining at rest Velocity and Acceleration
a = ΔvΔtΔvΔt = v f – v i t f – t i Average acceleration is the Change in velocity during some Measurable time interval. The SI unit for acceleration is m/s 2
A sprinter begins a race at 0.0 m/s And finished at 4.0 m/s. He does This in a time of 8s. What is his acceleration? 0.5 m/s 2
Instantaneous acceleration is The change in velocity at An instant of time. A velocity-time graph is a graph That show velocity on the X-axis and time on the y-axis.
The slope of a V-T graph will Give you acceleration.
There are a bunch of new formulas That can be found by deriving Them from the two basic formulas That we already know.
Displacement with Constant Acceleration Δd = ½ (v i + v f )Δt
A racing car reaches a speed of 42 m/s. It then begins a uniform Negative acceleration, using its Parachute and brakes, and comes To a stop 5.5s later. Find how far The car moves while stopping. 120 m
Velocity with Constant Acceleration v f = v i + aΔt Displacement with Constant Acceleration Δd = v i Δt + ½a(Δt) 2
A plane starting at rest at one end Of a runway undergoes a constant Acceleration of 4.8 m/s 2 for 15s Before takeoff. What is its speed at Takeoff? How long must the Runway be for the plane to Take off? 72 m/s540 m
Final Velocity after Any displacement v f 2 = v i 2 + 2aΔd
A babysitter pushing a stroller Starts from rest and accelerates At m/s 2. What is the Velocity of the stroller after it Has traveled 4.75 m? 2.18 m/s
Form to use when accelerating object has initial velocity. Form to use when accelerating object starts from rest. Δd = ½ (v i +v f )ΔtΔd = ½(v f )Δt v f = v i + aΔtv f = a(Δt) Δd = v i Δt + ½a(Δt) 2 Δd = ½a(Δt) 2 v f 2 = v i 2 + 2aΔdv f 2 = 2aΔd Equations for constantly Accelerated straight line motion
Free fall is the motion of an Object falling with a Constant Acceleration due To gravity.
All free falling bodies undergo A uniform acceleration Of 9.81 m/s 2. This acceleration, a, is given The new symbol, g.
A construction worker accidentally Drops a brick from a high scaffold. What is the velocity of the brick After 4 seconds? How far does the Brick fall during this time? 39 m/s 78 m