If you're on the road in car 2 going 20 m/s and car 1 is going 25 m/s in the dafne direction it would look as if it was passing you at 5 m/s west. This is because 25 m/s - 20 m/s = 5 m/s
When an element has a low specific heat, this means that it requires less energy to increase the temperature of this element. Specific heat is measure in Joules/GramDegreeCelcius because it measures the amount of joules required to raise one gram of the element by one degree Celcius.
Answer:
a) E = 6.4 1019 J b) v = 0.69 10⁴4 m / s
Explication
a) convert E = 4.0 eV
1 eV = 1.6 10⁻¹⁹ J
E = 4.0 eV (1.6 10⁻¹⁹ J / 1 eV)
E = 6.4 10⁻¹⁹ J
b) Suppose we have a frontal shock and all the kinetic energy of oxygen is transferred to Cs
Ei = K = ½ m v²
Ef = 6.4 10⁻¹⁹ J
½ m v² = 6.4 10⁻¹⁹
The oxygen mass of the periodic table is
PA = 15,999 u
1u = 1.660 10⁻²⁷ kg
Pa = 15,999 1,660 10⁻²⁷ kg
m= Pa = 26,558 10⁻²⁷ kg
Let's calculate the speed
v2 = 2 / m 6.4 10⁻¹⁹
v2 = 2 / 26,558 10⁻²⁷ 6.4 10⁻¹⁹ =
v = √0.4819 10⁸
v = 0.69 10⁴4 m / s
