Answer:
D. It has been demonstrated to be without exception under certain stated conditions.
Explanation:
A principle is simply a proposition based on some results from some experiments. A principle becomes a law when it gains strength. That is when other scientists support and back it.
A scientific law is a statement that describes a natural phenomenon and is not contradicted by repeated experiments over the time.
Sir Isaac Newton's law of gravitation stated "A gravitational force exists between all objects in the universe. This force is directly proportional to the masses of the two objects and inversely proportional to the distance between them."
His law explained that every body in the universe attracts every other body. It explained that it is not just Earth that pulls us towards it. But even sun and moon has their own gravitational pull and so does all other objects. It is just that the Gravitational pull of some objects is negligible.
Newton's law of Gravitation is considered a universal law because it is applicable to almost all the bodies in the universe and is demonstrated to be correct for them under certain conditions.
Answer:
a. 4
Explanation:
Hi there!
The equation of kinetic energy (KE) is the following:
KE = 1/2 · m · v²
Where:
m = mass of the car.
v = speed of the car.
Let´s see how would be the equation if the velocity is doubled (2 · v)
KE2 = 1/2 · m · (2 · v)²
Distributing the exponent:
KE2 = 1/2 · m · 2² · v²
KE2 = 1/2 · m · 4 · v²
KE2 = 4 (1/2 · m · v²)
KE2 = 4KE
Doubling the velocity increased the kinetic energy by 4.
Answer:
The correct option is (B).
Explanation:
The Kepler's third law of motion gives the relationship between the orbital time period and the distance from the semi major axis such that,
It is mentioned that, an asteroid with an orbital period of 8 years. So,
So, an asteroid with an orbital period of 8 years lies at an average distance from the Sun equal to 4 astronomical units.
Answer:
a) The maximum potential difference the wet human body can take = 5.88 V
b) This value is very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.
This means one should be very careful operating electrical appliances (even at home) while the body is wet.
Explanation:
From Ohm's law, V = IR
The resistance of the body when the body is wet = 1.2 kΩ = 1200 Ω
Maximum safe current that the body can withstand = 4.90 mA = 0.0049 A
Maximum voltage the body can withstand while wet = (Maximum safe current that the body can withstand) × (Resistance of the body when the body is wet) = 0.0049 × 1200 = 5.88 V
b) This value is still very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.
This means one should be very careful operating electrical appliances (even at home) while the body is wet.
