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:

Initial velocity = 
acceleration in the downward direction = -9.8 
Final velocity at the highest point = 0
Maximum height reached = 0.410 m
Now, Using third equation of motion:




Speed with which the flea jumps = 
D is the answer
To get the density you divide mass by volume
So the equation is 400/60=d
The first thing we need to do is figure out what equation to use. We will use the following kinematic equation...
Δx = (final velocity + initial velocity) x time / 2
We know that the car accelerates from rest, so initial velocity = 0 m/s
We also know final velocity = 20 m/s and time = 12s
Now we just need to plug everything in.
Δx = (20 x 12)/2 = 120 meters