Answer:
Open spaces in water's solid structure makes its solid state less dense than its liquid state.
Explanation:
- Water unlike other liquids is special. It contracts when cooled, down to a temperature of 4°C but thereafter begins to expand as it reaches 0°C and turns into ice.
- This property is useful for the preservation of marine life in very cold temperatures. During winter, the surface water in water lakes and rivers starts cooling. Upon reaching the temperature of 4°C, the surface water descends to the bottom as it denser.
- This help in the maintenance of temperature of the water at the bottom at 4°C. It is in this layer that marine life is sustained.
Answer:
ΔT=-747,13°C
Explanation:
Sensible heat is<em> the amount of thermal energy that is required to change the temperature of an object</em>, the equation for calculating the heat change is given by:
Q=msΔT
where:
- Q, heat that has been absorbed or realeased by the substance [J]
- m, mass of the substance [g]
- s, specific heat capacity [J/g°C] (
- ΔT, changes in the substance temperature [°C]
To solve the problem, we clear ΔT of the equation and then replace our data:
Q=msΔT
ΔT=Q/ms
Δ
°C
<em>(Note that Q=-14900 J because there is a </em><u><em>LOST</em></u><em> of thermal energy)</em>
Thus, the change in temperature of the steel bar is -747,13°C, meaning that the temperature of the bar decreases.
Answer:
ON
Explanation:
Frictional force is a force that opposes the motion of body. It is because of friction that motion can be controlled and even walking is made possible.
Now, on a frictionless surface, there is no opposition to motion. Therefore, to keep the body moving there is no force required.
- If surface lacks friction, motion will continue perpetually without any hinderance.
