Answer: 4.8 s
Explanation:
We have the following data:
the mass of the raft
the force applied by Sawyer
the raft's final speed
the raft's initial speed (assuming it starts from rest)
We have to find the time 
Well, according to Newton's second law of motion we have:
(1)
Where 
is the acceleration, which can be expressed as:
(2)
Substituting (2) in (1):
(3)
Where 
Isolating from (3):
(4)
Finally:
Answer:
The answer to your question is m₂ = 38.5 kg
Explanation:
Data
distance = d = 2.1 x 10⁻¹ m
Force = 3.2 x 10⁻⁶ N
m₁ = 55 kg
m₂ = ?
G = 6.67 x 10 ⁻¹¹ Nm²/kg²
Process
1.- To solve this problem use Newton's law of Universal Gravitation.
F = G m₁m₂ / r²
-Solve for m₂
m₂ = Fr² / Gm₁
2.- Substitution
m₂ = (3.2 x 10⁻⁶)(2.1 x 10⁻¹)² / (6.67 x 10⁻¹¹)(55)
3.- Simplification
m₂ = 1.411 x 10⁻⁷ / 3.669 x 10⁻⁹
4.- Result
m₂ = 38.5 kg
Frequency= velocity of light/wave length
Fr= 3×10^8/510×10^-9
Frequwency=5.88×10^14 Hz
More energy is released in nuclear reactions than in chemical reactions; this is because in nuclear reactions, mass is converted to energy. Nuclear energy released in nuclear fission and fusion is several 100 million times as large as an ordinary chemical reaction like the combustion process. The reason why nuclear energy release so much energy is because tremendous amounts of energy is released at one time. The nuclei in a nuclear reaction undergo a chain reaction, causing the neutrons to move extremely fast and release high amounts of energy.
(186,000 mi/sec) x (3,600 sec/hr) x (24 hr/da) x (365 da/yr)
= (186,000 x 3,600 x 24 x 365) mi/yr
= 5,865,696,000,000 miles per year (rounded to the nearest million miles)
