110 likes | 242 Views
Chapter Three Review. Vectors have a direction. Displacement Velocity Acceleration Force. Force 1. Force 2. 45°. 45°. What force will balance Force 1 and Force 2?. All vectors in two dimensions can be broken into an x and y component. 20 m. 20m(sin40°). 40°. 20m(cos 40°).
E N D
Vectors have a direction Displacement Velocity Acceleration Force
Force 1 Force 2 45° 45° What force will balance Force 1 and Force 2?
All vectors in two dimensions can be broken into an x and y component 20 m 20m(sin40°) 40° 20m(cos 40°)
Motion in the x direction is independent of motion in the y direction
vx = 20 m/s Dt = 1.43 s Dx = vxDt Dx = 28.6 m Dy = 10 m In a horizontally launched projectile, use the height to calculate the time in the air. Use vx to calculate how far it goes.
a b c d e
vx vy vi vx
A B 8 m 3 m C 40° 25° 4 m Find the resultant x = -8m(cos25°) + 3m(cos40°) + 4m = -.95m y = 8m(sin25°) + 3m(sin25°) = 5.31m
x = -.95m y = 5.31m q c2 = (-.95m)2 + (5.31m)2 c = 5.39 m tanq = 5.31m / -.95m q = -79.9° q = 180° - 79.9° = 100.1°
I throw a football at an angle of 50° with an initial velocity of 20 m/s. How far does it go? Dy = vi(sinq)Dt + (1/2)g(Dt)2 = 0 Dt = -2visinq/g = 3.12 s Dx = vi(cosq)Dt = 40.1 m