Answer:
The correct option is 'd': The change in shape of an object.
Explanation:
Since by definition physical change is defined as a change that changes only the form of an object or substance and producing no change in the chemical composition of the substance. Physical changes are reversible in nature.
As we can see from all the options the change in the shape of the object is a reversible change as we can always remold any substance in any shape, thus it confirms to a physical change.
The change in the molecular composition of an object is a hallmark of a chemical reaction thus indicates a chemical change.
The smell change in an object is an indication of a chemical change in the object hence is not a physical change.
<span>Minerals make up rocks. The role of minerals in rock formation is largely dependent on how the rock is formed.</span>
Answer:
(a). The kinetic energy stored in the fly wheel is 46.88 MJ.
(b). The time is 1.163 hours.
Explanation:
Given that,
Radius = 1.50 m
Mass = 475 kg
Power 
Rotational speed = 4000 rev/min
We need to calculate the moment of inertia
Using formula of moment of inertia

Put the value into the formula


(a). We need to calculate the kinetic energy stored in the fly wheel
Using formula of K.E

Put the value into the formula




(b). We need to calculate the length of time the car could run before the flywheel would have to be brought backup to speed
Using formula of time



Hence, (a). The kinetic energy stored in the fly wheel is 46.88 MJ.
(b). The time is 1.163 hours.
Visible range of electromagnetic radiation
The velocity of tennis racket after collision is 14.96m/s
<u>Explanation:</u>
Given-
Mass, m = 0.311kg
u1 = 30.3m/s
m2 = 0.057kg
u2 = 19.2m/s
Since m2 is moving in opposite direction, u2 = -19.2m/s
Velocity of m1 after collision = ?
Let the velocity of m1 after collision be v
After collision the momentum is conserved.
Therefore,
m1u1 - m2u2 = m1v1 + m2v2


Therefore, the velocity of tennis racket after collision is 14.96m/s