The natural abundances of elements in the human body, expressed as percent by mass, are oxygen (o), 65 percent; carbon (c), 18 percent; hydrogen (h), 10. percent; nitrogen (n), 3.0 percent; calcium (ca), 1.6 percent; phosphorus (p), 1.2 percent; all other elements, 1.2 percent. enter your answers in scientific notation. calculate the mass in grams of each element in the body of a 64−kg person.

O: 4.2 × 10⁴ g

C: 1.2 × 10⁴ g

H: 6.4 × 10³ g

N: 1.9 × 10³ g

Ca: 1.0 × 10³ g

P: 7.7 × 10² g

Other elements: 7.7 × 10² g

Explanation:

Natural abundances of elements in the human body (in percent by mass)

The mass of a body is 64 kg = 64 × 10³ g = 6.4 × 10⁴ g. We can calculate the mass of each element by multiplying the body weight by the mass percent of each element.

O: 6.4 × 10⁴ g × 65% = 4.2 × 10⁴ g

C: 6.4 × 10⁴ g × 18% = 1.2 × 10⁴ g

H: 6.4 × 10⁴ g × 10% = 6.4 × 10³ g

N: 6.4 × 10⁴ g × 3.0% = 1.9 × 10³ g

Ca: 6.4 × 10⁴ g × 1.6% = 1.0 × 10³ g

P: 6.4 × 10⁴ g × 1.2% = 7.7 × 10² g

Other elements: 6.4 × 10⁴ g × 1.2% = 7.7 × 10² g

un recipient conține 6,4 moli de gaz. gazul hidrogen reprezintă 25% din totalul kilometrilor din container. în cazul în care presiunea totală este de 1.24 atm ceea ce este

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied