Force = mass * acceleration
10 N - 2 N = 20 kg * acceleration
8 N = 20 kg * acceleration
8 / 20 = acceleration
2/5 m/s^2 = acceleration
Answer:The gravitational force on the ball due to earth is exactly the same as the gravitational force on earth due to the ball
Explanation:
The gravitational force exist in pair. It form action-reaction pair.
Answer:
Explanation:
Given that,
Half life = 12years
How long does it take to decompose form 655ppbm to 10ppbm.
Rate of decay is given as
Q=Qo• exp(-λt)
at t=0 Qo=655
Then, Q=10
λ is decay rate and it is
λ= In2 / t½
λ= In2/12
λ=0.05776
Therefore,
Q=Qo• exp(-λt)
10=655exp(-0.05776t)
10/655=exp(-0.05776t)
0.01527=exp(-0.05776t)
Take In of both sides
In(0.01527)=-0.05776t
-4.182=-0.05776t
Then, t=-4.182/-0.05776
t=72.4years
Then the time to decay to 10ppbm is 72 years and 3 months
Or 72 years approximately
Answer:
#_photons = 30 photons / s
Explanation:
Let's start by finding the energy of a photon of light, let's use the Planck relation
E = h f
the speed of light is related to wavelength and frequency
c = λ f
we substitute
E = h c /λ
E₀ = 6.63 10⁻³⁴ 3 10⁸/500 10⁻⁹
E₀ = 3.978 10⁻¹⁹ J
now let's use a direct proportion rule. If the energy of a photon is Eo, how many fornes has an energy E = 1.2 10⁻¹⁷ J in a second
#_photons = 1 photon (E / Eo)
#_photons = 1 1.2 10⁻¹⁷ /3.978 10⁻¹⁹
#_photons = 3.0 10¹
#_photons = 30 photons / s
That is False, kids shouldn't pick up heavy weights