D. There are two phosphate ions in a molecule of magnesium phosphate
Answer:
Pressure on both feet will be 
Explanation:
Weight of the person F = 500 N
Area of foot print 
Area of both the foot 
We have to find pressure on both the feet
Pressure is equal to ratio of force and area
So pressure 
So the pressure on both feet will be when person stands on both feet.
The force exerted by a pressure of any gas over a surface its given by the formula P=F/S (where P is pressure, F force and S surface).
We can multiply both sides of the formula by S to obtain the force.
P*S=(F*S)/S
P*S=F
Solve for P=1.80*10^5 Pa and S=4.10*10^-4 m^2 ([Pa] =[N/m^s])
(1.80*10^5 N/m^s) * (4.10*10^-4 m^2) =F
73.8 N =F
Answer:
4500 N
Explanation:
When a body is moving in a circular motion it will feel an acceleration directed towards the center of the circle, this acceleration is:
a = v^2/r
where v is the velocity of the body and r is the radius of the circumference:
Therefore, a body with mass m, will feel a force f:
f = m v^2/r
Therefore we need another force to keep the body(car) from sliding, this will be given by friction, remember that friction force is given a the normal times a constant of friction mu, that is:
fs = μN = μmg
The car will not slide if f = fs, i.e.
fs = μmg = m v^2/r
That is, the magnitude of the friction force must be (at least) equal to the force due to the centripetal acceleration
fs = (1000 kg) * (30m/s)^2 / (200 m) = 4500 N
