Regular Physics Chapter 4 Concept Development Page 11-16 Created for CVCA Physics By Dick Heckathorn 19 October 2K+4

Table of Contents CD 3 Statics p-11 6 Vectors & Equilibrium p-12 11 Force and Velocity Vectors p-13 14 Vectors and Equilibrium p-14 19 Force and Velocity Vectors p-15 22 Net Force p-16

The rock’s tendency to do this is called… 1. An astronaut in outer space away from all forces throws a rock. What will happen to the rock? inertia. What is inertia? How is it measured? grams /kg. CD p11

What is the path of the rock when the string breaks? 2. The rock is being whirled at the end of a string in a clockwise rotation. What is the path of the rock when the string breaks? A B C C D CD p11

3. The bus is traveling at 100 km/h. Its horizontal velocity is Relative to the bus, the pencil is traveling at… 100 km/h. As it drops, its horizontal velocity is 0 km/h. 100 km/h. Where will the pencil strike the floor? Where will the pencil strike the floor if the bus is at rest? Directly below where dropped. Directly below where dropped. CD p11

4. The force due to gravity on an object is called? weight The quantity of matter in an object is called? mass The amount of space an object occupies is called? volume CD p12

5. The force due to gravity on 1-kg is w = mg The mass with a weight of 98 N is 10 kg CD p12

Find ‘g’ on moon Click to show video clip of dropping hammer on the moon. Determine ‘t’ and ‘d’ and then find ‘g’ using d = ½ gt2. Click

6. Find the weight of your physics book. Then complete the table. Object Mass Weight Melon 1 kg _____ Apple ______ 1 N Physics Book Uncle Harry 90 kg 9.8 N 0.1 kg 882 N CD p12

7. Hit lead plate with hammer CD p12

300 300 150 300 CD p13

150 300 No!!! 100 150 300 No!!! CD p13

500 830 1000 CD p13

T Fs on r W Fe on r The rock hangs at rest. The net force on the rock is… What force(s) act on it? How do they compare? Zero. W Fe on r CD p14 CD p14

E W Fe on r B A FA on r FB on r The rock is suspended by two strings. There is a tension in each string. FA on r FB on r How big is each tension? W Fe on r The net force is … CD p14

E W Fe on r A B What is different here? The angles are different. Find the magnitude of A and B. B W Fe on r CD p14

E B A The tension is greater in A or B? W Fe on r CD p14

A B Fe on r B A Fe on r A B Fe on r CD p14 CD p14

Force Vectors CD p15

Force Vectors Velocity Vectors CD p15

The forces on the ball are? CD p15

4 Fnet = 4 Fnet = 1 3 4 CD p16

4 4 3 Fnet = 5 Fnet = 5 3 4 2 4 2 5 3 3 Fnet = 5 Fnet = 5 5 CD p16

9.9 9.9 7 CD p16

That’s all folks!