Section+5+chap+4

Section 5 toc

What Do You See?
page 392 5/11/11

the two different pictures have different way of measuring meat with pounds and meat

What Do You Think?
page 392 5/11/11

you can use the same scale because they measure both. A bathroom scale works by measuring the compression.

Investigate
page 392 5/11/11

Part A

1a. A unit of weight measurement b.no c. force exerted 2a. 686 3a. 64 and 176 4a. 49 b. 1.11 5a. 500 N

Part B

2a. it goes back in 3a. it goes out 4a. no 7a. 7b. 7c. 150 well be about 16 8a. it was fairly accurate 11b. the higher the stretch and weight the higher the fourth column is. e. its similar f. weight and stretch are constant
 * mass(g) || weight || stretch(cm) ||  ||
 * 0 || 0 || 5.5 || 0 ||
 * 20 || .196 || 7 || .028 ||
 * 50 || .49 || 9 || .054 ||
 * 70 || .686 || 10.5 || .065 ||
 * 100 || .98 || 12.5 || .072 ||
 * 120 || 1.176 || 14 || .084 ||

Part C

2a. 20 g 1.5 50 g 3 100 g 6.5 3a.

Physics Talk
page 396 5/11/11

Hooke's law: the restoring force exerted by a spring is directly proportional to the distance of stretch or compression of the spring. Fs= -kx Fs= force exerted by the spring x= the stretch (or compression) of the spring k= the spring constant weight: the force exerted on a mass as a result of gravity; the weight force on an object due to Earth is downward, in the vertical direction weight=mg

Checking Up
page 399 5/11/11

1. five times 2. the spring constant is an indication of how easy or difficult it is to stretch or compress a spring 3. a 1kg mass on Earth has a weight of 9.8 N 4. When you step on a scale the spring compresses just enough to provide un upward force equal to your weight

Physics To Go
page 402 4/13/11

1a. 980 b. 98 c. 580 w=mass*9.8 mass in kg w=N 1kg=2.2lbs my weight in pounds=132 lbs 59.9 2a. 520 b. 4000 c. 200 3a. c. .16 d. the sping constant 4. 12/3 = 4N/cm 5. When a force is applied to a string it will always stretch. 6. 15 N/cm will have more trouble stretching 7. 3/2 = 1.5 N/cm