Answer:
2.4 m/s
Explanation:
Momentum is conserved.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(0.08 kg)(0.5 m/s) + (0.05 kg)(0 m/s) = (0.08 kg)(-0.1 m/s) + (0.05 kg) v
0.04 kg m/s = -0.08 kg m/s + (0.05 kg) v
0.12 kg m/s = (0.05 kg) v
v = 2.4 m/s
Start with 2,000 grams.
After 1 half-life, 1,000 grams are left.
After another half-life, 500 are left.
After another half-life, 250 are left.
After another half-life, 125 are left.
That was FOUR half-lifes.
X = 4 .
Answer:
the correct one is D,
Ultraviolet, x-ray, gamma ray
Explanation:
Electromagnetism radiation are waves of energy that is expressed by the Planck relationship
E = h f
where h is the plank constant and f the frequency of the radiation.
Also the speed of light is
c = λ f
we substitute
E = h c /λ
therefore to damage the cells of the body radiation of appreciable energy is needed
microwave radiation has an energy of 10⁻⁵ eV
infrared radiation E = 10⁻² eV
visible radiation E = 1 to 3 eV
radiation Uv E = 3 to 6 eV
X-ray E = 10 eV
gamma rays E = 10 5 eV
therefore we see that the high energy radiation is gamma rays, x-rays and ultraviolet light.
When checking the answers, the correct one is D
