Which can occur in a physical change? The mass can increase. The particles can arrange in different ways. The mass can decrease. The atoms can bond to different atoms.

ill do it for 100, also this isnt 80 its 40

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

i think it's 35 meters

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west