There are 4 significant figures in 0.007890. These are 7890, which has non zeroes 7 8 9 and a trailing zero after the non zero. The leading zero or the zeroes before the non zero digit in a decimal is not considered to be significant numbers. Zeros can also be considered significant if they exist between non-zero numbers like 2018.
Answer:
d. the same within the uncertainty of each measurement method
Explanation:
The density of an object and in general any physical property, has the same value regardless of the method used to measure it, either directly or indirectly. Since two completely different valid methods are used, the results must be the same, taking into account the level of precision of each of the methods.
A can opener makes work easier by increasing force.
Explanation
Technically a can opener is a simple lever that increases the force with which we remove the cap of the can. Levers are rod shaped objects with fulcrum at one end and the length of the lever has a positive impact on the force.
considering the equation
work=force*distance
indicates that increasing the length of the lever/can opener increases the work done by it.
D. K = Potassium (use your periodic table)