Answer: The correct explanation is 2.
Explanation: The warm air is less dense (it expands) and thus it is lighter than the cold air so it will rise up to the floor. Therefore, when you place the heater on the floor it will warm the cold air which would then rise and be replaced by more cold air which would again get warm and rise and so on until the room is heated. This means that the correct explanation is 2.
On the other hand, if you put the heater at the ceiling, it will warm the cold air near the ceiling which would stay up there (it is lighter than the cold air under it). This means that the only way for the heat to spread from this ceiling level warm air to the lower levels is via conduction which is slow.
Answer:
139.514 metres
Explanation:
Initial velocity of the truck = 6.6 m/s
Acceleration of the truck = 2.8 m/s^2
Time interval = 7.9 s
Therefore we use the formula,
s = ut + 1/2 at^2
*where s(the distance travelled)...u(the initial velocity)...t(the time period)
; s = 6.6(7.9) + 1/2 (2.8)(7.9)^2
; s = 52.14 + 87.374
The distance moved by the truck = 139.514m
Answer:
<em>Total momentum is conserved</em>
Explanation:
<u>Conservation of Momentum
</u>
The momentum is a physical magnitude that measures the product of the object's velocity by its mass. The total momentum of a system is the sum of all its components' individual momentums. The two-bear system starts with a total moment of

When both bears stick together, the total mass is 20 kg, and the new momentum is

We have assumed both bears move to the right after the collision. In this situation, the total momentum is conserved