Complete Question:
A coin is dropped off of a building landing on its side. It hits with a pressure of 400 N/m². It hits with a force of 0.1N. Calculate the area of the coin?
Answer:
Area = 0.00025 m²
Explanation:
Given the following data;
Pressure = 400N/m²
Force = 0.1N
To find the area of the coin;
Pressure = Force/area
Area = Force/pressure
Substituting into the equation, we have;
Area = 0.1/400
Area = 0.00025 m²
450 J / 3 s = 150 J/s = 150 watts.
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:
c. 12,500
Explanation:
Original number of atoms = 100,000 atoms
Half- life = 10min
Unknown:
The number of atoms that will remain after 10min = ?
Solution:
The half - life is the time taken for half of a radioactive substance to decay by half.
Time taken Number of atom half life
10min 100000 _
20min 50000 1
30min 25000 2
40min 12500 3
The answer is B as all the other options contain quantities not related to describing motion
