Answer : Option D) Fixed-position pulleys are connected to a fixed point and do not move.
Explanation : As the name suggests the moving pulleys move freely whereas the fixed pulleys as per their name is attached to a fixed position and at a fixed point and they can not move freely.
Movable pulleys are ones which has one part of the rope attached to a fixed object, like a bar or a beam. Whereas when both the parts of a rope are attached to a fixed object, this is called as a fixed pulley.
Answer: Force F will be one-sixteenth of the new force when the charges are doubled and distance halved
Explanation:
Let the charges be q1 and q2 and the distance between the charges be 'd'
Mathematical representation of coulombs law will be;
F1=kq1q2/d²...(1)
Where k is the electrostatic constant.
If q1 and q2 is doubled and the distance halved, we will have;
F2 = k(2q1)(2q2)/(d/2)²
F2 = 4kq1q2/(d²/4)
F2 = 16kq1q2/d²...(2)
Dividing equation 1 by 2
F1/F2 = kq1q2/d² ÷ 16kq1q2/d²
F1/F2 = kq1q2/d² × d²/16kq1q2
F1/F2 = 1/16
F1 = 1/16F2
This shows that the force F will be one-sixteenth of the new force when the charges are doubled and distance halved
Answer:
A change is said be chemical change when a change in chemical property of a substance occurs and the new substance is chemically different from old one. A change is said to be physical change when only physical properties change but chemically the substances remain same.
a) adding sugar to lemonade- It is a physical change because sugar is being dissolves in the lemonade. There is no change in the chemical property.
b) plants using CO₂ and H₂O to form O₂ and sugar is a chemical change because new products which are chemically different are formed.
c) boiling water - is a physical change because only the physical state from liquid to gas changes. Chemically water retains its properties.
d) frying an egg - the properties of egg changes after frying. Hence, it is a chemical change. A fried egg does not retain properties of an uncooked one.
e) rust forming on metal- is a chemical change. Corrosion ( rusting) is a chemical change as rust is chemically different from the metal.
f) fruit rotting - is a chemical change. When microbes act on the fruit, the fruit starts to rot.
g) removing salt from water by evaporation- it is a physical change. The salt and water retain their physical properties as mixture and when separated by evaporation process.
impractical and modest
imaginative and original
unreasonable and outdated
Answer:
The correct answer will be option-imaginative and original.
Explanation:
The study of any natural phenomenon is based on the methods developed by humans. These methods are known as scientific methods as they approach the explanation in a systematic way.
The quest to understand the astronomical perspective-universe, planets and the planetary motions began around 2500 years ago which persists even today.
To understand the solar system researcher has to be a keen observer, imaginative and truthful to the evidence and data recorded. The logical imagination is essential to study the solar system as one is not able to see the far objects. This practicality allowed the researcher to think and rethink over the laws governing the systems.
Thus, option-imaginative and original is the correct answer.