1. 6-4 Connected Object The several objects tied together motion Separate these objects draw free body diagram: (1)Isolate the object (2)Draw the all external forces (3)Set up coordinate system (4)Resolve the force on x, y axes (5) apply Newton’s second law

2. m 1 =3.1kg, m 2 =4.4kg, find the acceleration? m1m1 m2m2 T T

3. Two blocks are connected by a string, as shown in Figure. The smooth inclined surface makes an angle of 35 0 with the horizontal, and the block on the incline has a mass of 5.7kg. The mass of the hanging block is m=3.2kg, Find acceleration. m 5.7kg 35 0

4. M=2kg, µ k =0.3, M=4kg, find accelerate and tension in rope. M m

5. 6-5 Circular Motion changing θθ v1v1 v2v2 v3v3

6. Object using the acceleration toward center of circle with magnitude centripetal acceleration This force causes circular motion and this centripetal acceleration is called the centripetal force.

7. Ex. Tension produces centripetal force Friction is centripetal force

8. Problem: A ball is bonded at v=3 m/s what is the tension in rope? r=1.2m (or r=3m) m=2kg Rounding a corner A 1200 kg car rounds a corner of radius r-45 m. if the coefficient of static friction between the tires and the road is µ s =0.82, what is the great speed the car can have in the corner without skidding.

9. Banked road: If a roadway is banked at the proper angle, a car can round a corner without any assistance from friction between the tires and the road. Find the appropriate banking angle for a 900- kg car travelling at 20.5 m/s in a turn of radius 85.0m. θ W N