Answer:
1. the force which can be felt or act only when two objects are in contact is known as contact force.
for example: frictional force, muscular force,
tension, air resistance .
2. the force which can be felt or act even when two objects are in contact or not is known as non-contact force.
for example: magnetic force, gravitational force, electrostatic force.
Answer:
A. Splitting water into hydrogen and oxygen.
Explanation:
A chemical change produces a new substance. ... A physical change does not produce a new substance. Changes in state or phase (melting, freezing, vaporization, condensation, sublimation) are physical changes.
Weight = (mass) x (gravity)
120 N = (mass) x (9.8 m/s²)
Mass = (120 N) / (9.8 m/s²)
Mass = 12.24 kg (B)
Complete question:
(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C
Answer:
The energy that must be supplied to boil the given mass of the water is 672,000 J
Explanation:
Given;
mass of water, m = 2 kg
heat of vaporization of water, L = 330 kJ/kg
initial temperature of water, t = 20 ⁰C
specific heat capacity of water, c = 4200 J/kg⁰C
Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;
Q = mc(100 - 20)
Q = 2 x 4200 x (80)
Q = 672,000 J
Q = 672,000 J
Q = 672,000 J
Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J
Answer:
3.7 N/kg
Explanation:
The gravitational strength refers to the amount of gravity acting per unit mass. Hence in this case,
Gravitational Strength = Weight / Mass
= 370 / 100
= <u>3</u><u>.</u><u>7</u><u>N</u><u>/</u><u>k</u><u>g</u>
