Chapter 4 Other Force Diagrams

1. Chapter 4 Other Force Diagrams

2. W|| W 28° Ff Find Ff : Find FNET : Find FA : FN FA =.675(51.9) = 6(3.5) FA – 27.6 – 35 = 21 = 35.0 N = 21.0 N 83.6 N But first one RAMP PROBLEM for review………. With what force must you push to accelerate a 6.00 kg block 3.50 m/s2 UP a 28° ramp with  = .675? FN = W FA – W|| - Ff = FNET 6 58.8 51.9 27.6 m = W = W= W||= Ff =  FN FNET = ma FA – W|| - Ff = FNET

3. Handout

4. What is the acceleration of a 20.0 kg object when pulled with a rope that makes an angle of 22° with the horizontal? The applied force on the rope is 250 N and  = .333. FA W FN F 250 F|| 250 sin = cos = 250 F Ff F|| F 250 F|| FN + F = W F|| - Ff = FNET m = W= FA= F= F||= 20 250 196 93.7 232

5. What is the acceleration of a 20.0 kg object when pulled with a rope that makes an angle of 22° with the horizontal? The applied force on the rope is 250 N and  = .333. FA W FN Find FN: Find Ff : Find FNET: Find a: Ff F 250 F|| FN + F = W F|| - Ff = FNET m = W= FA= F= F||= 20 196 250 93.7 232 Ff =  FN FN + F = W F|| - Ff = FNET FNET = ma FN+ 93.7 = 196 =.333(102) 232 – 34 = FNET 198 = 20 a 102 N 34.0 N 198 N 9.90 m/s2

6. What is the coefficient of friction if pulling with 55.0 N on a handle that makes an angle of 35° with the ground gives a 60.0 N object an acceleration of 3.00 m/s2? FN F 55 F|| Ff W Find FNet: Find Ff : Find FN: Find : FN + F = W F|| - Ff = FNET m = W= FA= F= F||= 6.12 60.0 55 31.5 45.1 FNET = ma F|| - Ff = FNET FN + F = W Ff =  FN = 6.12(3) 45.1 – Ff = 18.4 FN + 31.5 = 60 26.7=  (28.5) 18.4 N 26.7 N 28.5 N .937