No the density does not change. Density is a ratio D=m/v no matter how much of a substance you have its mass will be proportional.
When doing density labs sometimes you might get different answers due to errors that are unavoidable.
Answer:
The Mass of a person is calculated to be 28.6kg .
Explanation:
This is based on Kinetic energy and we know, that Kinetic energy is the energy possessed by body by virtue of its motion .
It can be calculated by expression :
K.E=1/2mv²
Velocity of a person = 11.2m/sec
Kinetic energy = 1800J
Mass of person = ?
We know ,
K.E=1/2mv²
so, putting values we have :
1800=1/2 x m x (11.2)²
That is ,
m=1800 x 2 /11.2 x 11.2
or
m=3600/125.44
m = 28.6 kg
Answer:
10 seconds
Explanation:
because the cat is moving one m/s slower than the dog, the dog has a relative speed of 1 m/s. 10 meters would take 10 seconds for the dog to cover
Answer:
27 blocks
Explanation:
First, the expression to use here is the following:
P = F/A
Where:
P: pressure
F: Force exerted
A: Area of the block.
Now , we need to know the number of blocks needed to exert a pressure that equals at least 2 atm. To know this, we should rewrite the equation. We know that certain number of blocks, with the same weight and dimensions are putting one after one over the first block, so we can say that:
P = W/A
P = n * W1 / A
n would be the number of blocks, and W1 the weight of the block.We have all the data, and we need to calculate the area of the block which is:
A = 0.2 * 0.1 = 0.02 m²
Solving now for n:
n = P * A / W1
The pressure has to be expressed in N/m²
P = 2 atm * 1.01x10^5 N/m² atm = 2.02x10^5 N/m²
Finally, replacing all data we have:
n = 2.02x10^5 * 0.02 / 150
n = 26.93
We can round this result to 27. So the minimum number of blocks is 27.
