Answer:
Density of 18.0-karat gold mixture is .
Explanation:
A mixture of 18 parts gold, 5 parts silver, and 1 part copper.
Let mass of gold be 18x
Let the mass of silver be 5x
Let the mass of copper be 1x
The density of gold =
The density of silver =
The density of copper =
Volume of the gold in the mixture =
Volume of the silver in the mixture =
Volume of the copper in the mixture =
Mass of the mixture = M = 18x+5x+1x =24x
Volume of the mixture =
Density of the mixture:
First we need to convert the angular speed from rpm to rad/s. Keeping in mind that
the angular speed is
And so now we can calculate the tangential speed of the child, which is the angular speed times the distance of the child from the center of the motion:
Answer:
a)
b)
c)
d) would be the same.
would decrease.
would be the same.
Explanation:
a) On an inclined plane the force of gravity is the sine component of the weight of the block.
b) The friction force is equal to the normal force times coefficient of friction.
c) The work done by the normal force is zero, since there is no motion in the direction of the normal force.
d) The relation between the vertical height and the distance on the ramp is
According to this relation, the work done by the gravity wouldn't change, since the force of gravity includes a term of .
The work done by the friction force would decrease, because both the cosine term and the distance on the ramp would decline.
The work done by the normal force would still be zero.
That's good ! I never heard of that before. (Maybe because
I've never been stung by an ant.)
When an ant bites or stings, it injects a tiny amount of 'formic acid'
into your skin. Soon, the formic acid itches, burns, and stings, and
after a while, a little piece of skin dies and falls off. Some people
are seriously allergic to it, and it can make them really sick.
'Acids' and 'bases' are opposites, and one can neutralize (cancel out)
the other. Tony is putting a weak 'base' on the sting, to neutralize the
formic acid that the ant left him as a little gift.