Physics, 19.09.2019 08:50 leilaford2003

Did the bigbang violate the law of conservation of energy and matter?

Answers: 1

Show answers

Answers

Under general relativity, there is no 'before the Big Bang'. The problem is that time is itself a part of the universe and is affected by matter and energy. Because of the huge densities just after the Big Bang, time itself is warped in such a way that it cannot go back before that event. It is somewhat like asking what is north of the north pole.

The conservation of matter and energy states that the total amount of mass and energy at one time is the same at any other time. Notice how time is a crucial part of this statement. To even talk about conservation laws, you have to have time.

The upshot is that the Big Bang did not break the conservation laws because time itself is part of the universe and started at the Big Bang and because the conservation laws need to have time in their statements.

Answer from: Quest

weight of the box is given as

$w = 112.1 n$

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

$w_x = w sin\theta$

here we have

$w = 112.1 n$

$w_x = 112.1 sin42$

$w_x = 75 n$

so it requires 75 n force to move it upwards

Answer from: Quest

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

$f\alpha \frac{dp}{dt}$

⇒ $f= k \frac{dp}{dt}$

here k is the proportionality constant whose value is 1.

$f=\frac{dp}{dt}$

$f= \frac{d[mv]}{dt}$

$f= m\frac{dv}{dt} +v\frac{dm}{dt}$

$f=ma+v\frac{dm}{dt}$ [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

Another question on Physics

Physics, 21.06.2019 18:40

What best describes a sonar wave? transverse and electromagnetic transverse and mechanical longitudinal and electromagnetic longitudinal and mechanical

Answers: 1

Answer

Physics, 22.06.2019 15:00

What is the role of lenses in microscopy?

Answers: 2

Answer

Physics, 22.06.2019 15:30

What is a costume plot? why is it important to a film or theater production?

Answers: 3

Answer

Physics, 22.06.2019 16:10

To a of 4 x hz is 1. 0. mm nm nm