INTRODUCTION
A)  fill the blank for full credit
bank:  Newton, push, EArth, 9.8, magnitude,mass,  direction, pull
A force is a ________ or a _________. A force has a _________ and a ___________. The weight is the downward force exerted by the ________ on an object. The symbol is W. The direction is toward the center of the _________.
A force like the weight is measured in ________. weight (in newtons) = ______ (in Kg) x _____ (in m/s/s)
B) compute:
You will be working with a mass of 200g. 200g = _____kg .  The weight  = _______ N
To convert grams to newtons, you divide the mass in grams  by about ______.

PROCEDURE !! BEFORE doing the experiment, predict the outcome. Of course, it does not
matter if you got the prediction wrong, you are learning using a scientific method.
you will need: spring scales (3) with units in newton, a mass of 200g, a stick, string, ring stand

experiment 1: (write the prediction first)
you will hang 200g on your spring scale (see figure below).

Predict :  the reading:  in grams  ______ ,in Newtons _______

Measurements: _______g = ________ N.
From now on, to make the measurements easier, the reading will be in gram only. It is still like measuring a force
since  the mass in grams is proportional to the weight anyway. (You just need to divide by about 100)



experiment2: 2 spring scales and the mass. Before doing the experiment, predict the outcomes.

Predict the reading on each scale:
reading 1 = _____________ g , reading 2 = __________g

Do the experiment.
reading 1 = _________ g, reading 2 = ______________g


The force exerted by the mass is transmitted to the first spring scale.







experiment3: 2 spring scales, the stick  and the mass. Before doing the experiment, predict the outcomes.

Predict reading for each scale _________g and __________ g

Check by doing it: _______g and ________g
3 forces act on the stick : ________g@ down, _________g @ up, ______g@ up
The down force = Sum of the ________ forces. This is consequence of Newton's second law.
(you will learn about Newton's second law in 10th gradE)



experiment4: 3 spring scales, the stick  and the mass. Before doing the experiment, predict the outcomes.

Predict reading for each scale _________g ,  __________ g, and ________g

Check by doing it: _______g , ______g, and ________g
4 forces act on the stick : ________g@ down, _________g @ up, ______g@ up, ______g@ up
The down force = Sum of the ________ forces.




experiment 5: do the predictions  before doing the experiments
Predict the reading : ___________g

check : ________________g
The weight pulls on the string, the string pull back on the weight with the same force.
(Newton's third law) This pull is called a tension.
If we neglect the mass of the string, the tension in the string = weight




experiment 6: do the predictions before doing the experiments.

Predict the reading __________g, ______________g

Check _____________g, _____________g









experiment 7: do the predictions before doing the experiments.

Predict reading _____________g

check : ____________g









experiment 8 : predict outcomes first.


Predict reading ________________g

Check: _____________________g











experiment9: Make up your own experiment and predict the outcomes. Sketch your set up. Check your prediction.