If the fan blades rattle while the fan is turning, you can stop the noise by
a. oiling the blades.
b. adjusting the blade angles and the blade tip position.
c. tightening the motor end bells and motor mounts.
d. cleaning the blade surfaces

Click the game tab at the bottom of the simulation and select level 1. (there is no seesaw balance for this part of the activity.) balance the first equation, and click check to see if you got it right. if you can’t balance it in the first try, you can try again. work through the five equations for level 1. click continue to go on to level 2, and later level 3. each level is more difficult than the one before. keep trying until all the equations are balanced. in one or two sentences, describe how you did in the balancing game. in a few more sentences, explain one strategy you learned for balancing more complex equations.