Answer:
a) 4.2m/s
b) 5.0m/s
Explanation:
This problem is solved using the principle of conservation of linear momentum which states that in a closed system of colliding bodies, the sum of the total momenta before collision is equal to the sum of the total momenta after collision.
The problem is also an illustration of elastic collision where there is no loss in kinetic energy.
Equation (1) is a mathematical representation of the the principle of conservation of linear momentum for two colliding bodies of masses 
and 
whose respective velocities before collision are 
and 
;
where 
and 
are their respective velocities after collision.
Given;
Note that =0 because the second mass was at rest before the collision.
Also, since the two masses are equal, we can say that 
so that equation (1) is reduced as follows;
m cancels out of both sides of equation (2), and we obtain the following;
a) When 
, we obtain the following by equation(3)
b) As stops moving 
, therefore,
Density = (mass) / (volume), no matter how large or small the sample is.
We can't calculate the density, because you left out the number for the volume.
Also, you didn't tell us the unit for the mass of 180.
a). If the mass is 180 grams, then the density is
(180 gm) / (volume) .
b). No matter how many pieces you crush it into, and
no matter how large or small a piece is, its density is
the same. (I just wish we knew what the density really is.)
c). A piece may have 80 grams of mass. It doesn't "weigh" 80 grams.
Since the density of the whole rock is (180 gm) / (volume),
the density of any piece of it is (180 gm) / (volume).
Multiply each side by (volume): (Density) x (volume) = 180 gm
Divide each side by (density): Volume = (180 gm) / (density)
We can't calculate the volume of an 80-gm piece, because
we don't know the density. (That's because you left the volume
out of the question.)
Answer:
velocity because it says you are going 3 miles north and velocity is something going a speed in a certian direction
Explanation:
Fill in the blank --
A radio controlled car rolls 10 m south, then reverses direction and rolls 8 m north.
The car has traveled a distance of 18 m and has a displacement of 2 m south
↑ ↑ ↑ Hope this helps! (The bolded number is the unknown value/blank)
