Simple applications Of 1st & 2nd Laws

Applications of Newton’s Laws vo= 20 m/s m = 5 kg v = 0 F m d Find distance block moves

inside a stationary elevator. A man stands on a scale inside a stationary elevator. Forces acting on the man N Reading on scale mg Dynamics: Newton’s Laws of Motion

When Moving Upward With Constant Velocity Forces acting on the man v N mg Reading on scale Dynamics: Newton’s Laws of Motion

When Moving Upward With Constant Acceleration Forces acting on the man a N mg Reading on scale Dynamics: Newton’s Laws of Motion

When Moving Downward With Constant Acceleration Forces acting on the man a N mg Reading on scale Dynamics: Newton’s Laws of Motion

Determine the magnitude of the forces acting on each of the 2 kg masses at rest below. 30° 30° 30° 60°

∑Fx = 0 and ∑Fy = 0 mg = 20 N N = 20 N

∑Fx = 0 and ∑Fy = 0 T1 = 10 N 20 N T2 = 10 N

30° mg = 20 N T1 = 20 N T2 = 20 N Method 1: ∑Fx = 0 and ∑Fy = 0 Method 2: ∑F = 0

∑Fx = 0 and ∑Fy = 0 Method 1: ∑Fx = 0 and ∑Fy = 0 Method 2: ∑F = 0 30° T1 = 40 N T2 = 35 N Method 1: ∑Fx = 0 and ∑Fy = 0 Method 2: ∑F = 0

A Harder Problem! a. Which string has the greater tension? b. What is the tension in each string? 30° 60°

Applications of Newton’s Laws Find Tensions T1 and T2 q T1 sin(60) T1 cos(60) T1 T2 mg m q = 60o m = 20 kg

Applications of Newton’s Laws Another method q T1 q mg T1 T2 T2 mg m

Applications of Newton’s Laws Three mass system - find acceleration F m 2m 3m Find the tensions in the string. First find the acceleration of the system. Laws of Motion (Chapter 4) 2053.ppt

T2 F m 2m 3m Three mass system - find T2 Laws of Motion (Chapter 4) 2053.ppt

T1 T2 F m 2m 3m Three mass system - find T1 Laws of Motion (Chapter 4) 2053.ppt

If Hand force is 150N Find the acceleration of the system With what force does the 5kg block push on the 10 kg block?