Explanation:
formula: <u>Mass</u>
Density x volume
2a) m=10kg v=0.3m³
10÷0.3=33.3 kg/m
2b) m = 160 kg V=0.1m³
160÷0.1=1600 kg/m
2c) m = 220 kg V = 0.02m³
220÷0.02=11000 kg/m
A wooden post has a volume of 0.025m³ and a mass of 20kg. Calculate its density in kg/m.
density = volume ÷ mass
20÷ 0.025=800 kg/m
Challenge: A rectangular concrete slab is 0.80m long, 0.60 m wide and 0.04m thick. Calculate its volume in m³.
Formula : Length x width x height = Volume
0.80 x 0.60 x 0.04 = 0.0192m³
B) The mass of the concrete slab is 180 kg. Calculate its density in kg/m.
density = volume ÷ mass
180 ÷ 0.0192 = 9375 kg/m
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.
<u>Answer:
</u>
Cat has 2.02 seconds to right itself.
<u>Explanation:
</u>
Initial height of cat from ground = 20 meter.
We have equation of motion , 
, s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
In this the velocity of cat in vertical direction = 0 m/s, acceleration = acceleration due to gravity = 9.8 
, we need to calculate time when s = 20 meter.
Substituting
So, cat has 2.02 seconds to right itself.
Kinetic energy is greatest at the lowest point of a roller coaster and least at the highest point
Electric field, an electric property associated with each point in space when charge is present in any form. The magnitude and direction of the electric field are expressed by the value of E, called electric field strength or electric field intensity or simply the electric field.
Magnetic field are a region around a magnetic material or a moving electric charge within which the force of magnetism acts. Magnetic fields are produced by moving electric charges. Everything is made up of atoms, and each atom has a nucleus made of neutrons and protons with electrons that orbit around the nucleus. Since the orbiting electrons are tiny moving charges, a small magnetic field is created around each atom.
Similarities between magnetic fields and electric fields: Magnetic fields are associated with two magnetic poles, north and south, although they are also produced by charges (but moving charges). Like pole repel unlike poles attract. Electric field points in the direction of the force experienced by a positive charge.
