Answer:
A substance in its liquid state is closer to the density of its solid phase than the density of its gaseous phase.
Explanation:
For a substance in its liquid state we can expect the density of the substance more closer to the density of its solid state than its gaseous state because the the inter-molecular space is much close near to incompressible in the liquid state and the the inter-molecular force of attraction is much higher as compared to gaseous state.
In contrast to the molecular properties in liquid state gases have almost negligible inter-molecular force of attraction and very huge inter-molecular spacing which makes it well compressible.
Answer:
Closed system, because the speed of the car is as expected in the case where an object has uniform acceleration for a time t
Explanation:
Here in the question it is mentioned that a toy car has an initial acceleration of 2m/s² across a horizontal surface so we can say that it is acted upon by an external force
Assuming that the acceleration is constant and the reason for this assumption is there at the last
The major difference between an open system and closed system is in case of open system there will be transfer of matter and in case of closed system there will be no change in matter of the system
If acceleration is constant in case of closed system we can expect the speed of the car after a time t by using the formula
s = u×t + 0·5×a×t²
where s is the distance travelled
t is the time taken to travel that distance
u is the initial velocity
a is the acceleration of that system
But in case of open system as there will be a change of mass there will be a change in velocity of the system so in this case we cannot expect the speed of the car after a time t
And if the acceleration is not constant then we cannot say that the toy car is an open system or closed system, that is why we are assuming that the acceleration of the toy car is constant
If this is about simple machines the answer is: Inclined plane
