Using the formula F = m*a. where F is the force, m is the mass and a is the acceleration you can use it for each. As long as there are no other forces towards the body in both cases :
F = m*a
F = 50*3
F = 150 N
Answer:
- 0.09 % of the original radioactive nucllde its left after 10 half-lives
- It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Explanation:
The equation for radioactive decay its:
,
where N(t) its quantity of material at time t,
its the initial quantity of material and
its the mean lifetime of the radioactive element.
The half-life
its the time at which the quantity of material its the half of the initial value, so, we can find:

so:




So, after 10 half-lives, we got:




So, we got that a 0.09 % of the original radioactive nucllde its left.
Putonioum-239 has a half-life of 24,110 years. So, 10 half-life will take to pass

It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
b. The guitar represents half of the wave length. So the full wave length is 2x0.9m = 1.8m.
Using the given equation, v= λ ∙ f,
the wave is moving back and forth along the string at 1.8 ∙ 256
= 460.8m/s
c. Sound waves travel at 6,000 m/s.
Using the given equation, v=d/t, or d=vt,
train's vibration in 3 seconds travels 6000*3
=18,000m or 18km
m₁ = mass of the first object = 3.0 kg
m₂ = mass of the second object = 3.0 kg
r = distance between the first and second object = 1.0 m
G = universal gravitational constant = 6.67 x 10⁻¹¹ N m²/kg²
F = force of gravity between the two objects = ?
according to law of gravitation, force of attraction "F" between two objects m₁ and m₂, placed distance "r" apart is given as
F = G m₁ m₂/r²
inserting the values
F = (6.67 x 10⁻¹¹) (3.0) (3.0)/(1.0)²
F = (6.67 x 10⁻¹¹) (9.0)
F = 60.03 x 10⁻¹¹ N
F = 6.003 x 10⁻¹⁰ N