Answer:
De cual Tema??? jajaja no se que necesitas
A physical quantity is something which can be measured and whose measurement is necessary because all the laws of physics are given in terms of these physical quantities. The examples of physical quantity are mass, length, time, temperature, electric current, velocity , acceleration, force, work, weight,power, energy etc.
There are some quantities which cannot be measured and hence are not classified as physical quantities , for example, love, honesty, hatred etc
Thus a physical quantity is a quantity which can be measured.
Answers:
a) 5400000 J
b) 45.92 m
Explanation:
a) The kinetic energy
of an object is given by:

Where:
is the mass of the train
is the speed of the train
Solving the equation:

This is the train's kinetic energy at its top speed
b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:


Where:
is the train's initial kinetic energy
is the train's initial potential energy
is the train's final kinetic energy
is the train's final potential energy, where
is the acceleration due gravity and
is the height.
Rewriting the equation with the given values:

Finding
:
Compared to the pucks given, the pair of pucks will rotate at the same rate.
Answer: Option A
<u>Explanation:</u>
The law of conservation of the angular momentum expresses that when no outer torque follows upon an article, no difference in angular momentum will happen. At the point when an item is turning in a shut framework and no outside torques are applied to it, it will have no change in angular momentum.
The conservation of the angular momentum clarifies the angular quickening of an ice skater as she brings her arms and legs near the vertical rotate of revolution. In the event, that the net torque is zero, at that point angular momentum is steady or saved.
By twice the mass yet keeping the speeds unaltered, also twice the angular momentum's to the two-puck framework. Be that as it may, we likewise double the moment of inertia. Since
, the turning rate of the two-puck framework must stay unaltered.