the number of electrons that fill the outer shell determines the properties of elements
Answer: Energy can neither be created nor destroyed, rather it is converted from one form to another
Explanation:
The principle of conversation of energy explains how energy is conserved in nature by being converted from one form to another such that no energy is created nor destroyed.
Practical examples include:
- electrical pressing iron that converts electrical energy to heat energy
- solar panels that converts solar energy to electrical energy
- Car batteries that converts chemical energy to light energy etc
Answer:
Part a)
Part b)
Explanation:
As we know that two carts are moving in opposite directions
so here total momentum of two carts must be given by vector subtraction
It is given as
Now we know that total momentum of the system is conserved here as there is no external force on this system
so the speed of the first cart when second cart was at rest is given as
Answer:
686.7N
Explanation:
Given data
Mass= 70kg
We know that the buoyant force experienced by the person is equal to the weight of the person
Hence the weight is
Weight = mass* Acceleration
Weight= 70*9.81
Weight= 686.7N
Therefore the weight is 686.7N
Answer:
Explanation:
Let the velocity of rocket case and payload after the separation be v₁ and v₂ respectively. v₂ will be greater because payload has less mass so it will be fired with greater speed .
v₂ - v₁ = 910
Applying law of conservation of momentum
( 250 + 100 ) x 7700 = 250 v₁ + 100 v₂
2695000 = 250 v₁ + 100 v₂
2695000 = 250 v₁ + 100 ( 910 +v₁ )
v₁ = 7440 m /s
v₂ = 8350 m /s
Total kinetic energy before firing
= 1/2 ( 250 + 100 ) x 7700²
= 1.037575 x 10¹⁰ J
Total kinetic energy after firing
= 1/2 ( 250 x 7440² + 100 x 8350² )
= 1.0405325 x 10¹⁰ J
The kinetic energy has been increased due to addition of energy generated in firing or explosion which separated the parts or due to release of energy from compressed spring.
