This assumption is correct. The emissivity of a substance is the ratio of the energy radiated from a body to the energy radiated from a black body (perfect emitter). Because these stars reflect negligible radiation compared to the amount they emit.
By definition, the law of conservation of energy states that:
Ei = Ef
Where,
Ei: initial energy
Ef: final energy
Therefore, no matter the type of energy, always the final energy is equal to the final energy.
Energy can be transformed into another type of energy. For example, the potential energy can be transformed into kinetic energy.
Also, energy is not created, nor destroyed.
Answer:
The following is not true about the Law of Conservation of Energy:
A. It states that the total energy in the universe keeps increasing.
In particle kinematics, we measure the acceleration of the particle. For this, an observer is taken as a reference point. Generally we consider the observer as in origin of a co-ordinate system. The place where observer is placed is known as frame of reference.
Newton's laws only work in the inertial frame of reference. Inertial frame is a frame of reference whose acceleration is zero. But, if you are observing the motion of an object from non-inertial frame, you need to add and extra force on the system under observation which is known as pseudo force.
The mosquito exerts the same force on the car as the car exerts on the mosquito.
Answer:
1.31Kgms-1
Explanation:
∆p = m∆v
Where:
∆p= change in momentum
m= mass of the ball
∆v= change in velocity of the ball= (5.3-2.4)= 2.9ms-1
Therefore, substituting appropriately with the values above:
∆p= 0.45×2.9= 1.31Kgms-1
