Remember:
a^m * a^n=a^(m+n)
a^-m=1/a^m
8³ x 8⁻⁵=8³⁻⁵=8⁻²=1/8²=1/64<1
Answer: the student is not correct, because 1/64<1, and 8³ x 8⁻⁵=1/64.
43 ........................................
Answer:
Metals which react with steam form the solid metal oxide and hydrogen gas.
In general, the more reactive the metal, the more rapid the reaction. Aluminium is unusual, because it is a reactive metal that does not react with water. Its surface forms a protective layer of aluminium oxide that keeps water away from the metal below.
The apparatus used to react a metal with steam and collect the gas produced is shown below.
9514 1404 393
Answer:
68.6 m/s
Step-by-step explanation:
The speed at a given time is the derivative of the height at that time.
dh/dt = -9.8t
At t=7, the speed is ...
-9.8(7) = -68.6 . . . . . meters per second (downward)
The speed is 68.6 meters per second.
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<em>Additional comment</em>
Height is considered to be positive in the up direction, so velocity and acceleration are also positive in the up direction. The derivative of height will be the velocity. Its negative sign in this case indicates the object is moving in the downward direction. The speed is the magnitude (absolute value) of the velocity.
Answer:
The dot all the way on the left. The one between 2 and 3 I believe.
Step-by-step explanation:
