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: 15.87 m
From the equation of motion:
where, 
is the distance traveled, 
is the initial velocity, 
is the acceleration and 
is the time.
The rock free falls under gravity. Initial velocity, 
, 
It took 
for rock to hit the water.
Substitute the values in the given equation:
Hence, the water is 15.87 m below the top level of the well.
Consider the motion towards right as positive and motion towards left as negative.
m₁ = mass of the cart moving to right = 0.500 kg
v₁ = initial velocity before collision of the cart moving towards right = 2.2 m/s
m₂ = mass of cart moving to left = 0.800 kg
v₂ = initial velocity before collision of the cart moving towards left = - 1.1 m/s
initial momentum of the system of carts before the collision is given as
P₁ = m₁ v₁ + m₂ v₂
P₁ = (0.500) (2.2) + (0.800) (- 1.1)
P₁ = 0.22 kg m/s
P₂ = momentum of system of carts after collision
As per conservation of momentum,
Momentum of system of carts after collision = Momentum of system of carts before collision
P₂ = P₁
P₂ = 0.22 kg m/s
The circulatory system is important in meeting the needs of all cells in the body because it offers means of transport by which cells obtain the materials needed to live and function.
The functions of the circulatory system by which the cells are supported include:
1. Respiration- oxygen is delivered to the cells and carbon dioxide is removed from them.
2. Nutrition- nutrients for energy are supplied to every cell in the body.
3. Waste removal- metabolic waste products are taken away before they accumulate and become harmful to the cells.
4. Cellular communication- hormones are transported to the cells and organs that need them for proper functioning.
5.Thermoregulation- As blood circulates, it keeps body temperature balanced and thus cells are able to carry out processes well.
The high temperature of the heated air inside the balloon causes the air particles to spread out. This leads to a lower density compared to colder air surrounding the balloon.
Therefore the low density causes the balloon to rise up.
