Answer:
0.39 km west
Explanation:
The position of Runner A is:
x = -5.7 + 8.8 t
The position of Runner B is:
x = 4.2 − 7.6 t
When the positions are equal:
-5.7 + 8.8 t = 4.2 − 7.6 t
16.4 t = 9.9
t = 0.604
Plug into either equation to find the position at this time:
x = -5.7 + 8.8 (0.604)
x = -0.39
The runners are 0.39 km west of the flagpole when they meet.
Answer:
Aerobic exercise reduces the risk of many conditions, including obesity, heart disease, high blood pressure, type 2 diabetes, metabolic syndrome, stroke and certain types of cancer. Weight-bearing aerobic exercises, such as walking, help decrease the risk of osteoporosis.
Answer:
Explanation:
A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:
(1)
Where:
- Change in kinetic energy of the system, measured in joules.
- Change in gravitational potential energy of the system, measured in joules.
If we know that 
and 
, then we get the following equation:
(2)
Where 
and 
stands for initial and final states of each energy component.
Hence, the right answer is
Answer:
the relative speed should be 40mph
Explanation:
Answer:
What is freezing point?
A liquid's freezing point is determined at which it turns into a solid. Corresponding to the melting point, the freezing point often rises with increasing pressure. In the case of combinations and for some organic substances, such as lipids, the freezing point is lower than the melting point. The first solid which develops when a combination freezes often differs in composition from the liquid, and the development of the solid alters the composition of the remaining liquid, typically lowering the freezing point gradually. Utilizing successive melting and freezing to gradually separate the components, this approach is used to purify mixtures.
What is melting point?
The temperature at which a purified substance's solid and liquid phases may coexist in equilibrium is referred to as the melting point. A solid's temperature goes up when heat is added to it until the melting point is achieved. The solid will then turn into a liquid with further heating without changing temperature. Additional heat will raise the temperature of the liquid once all of the solid has melted. It is possible to recognize pure compounds and elements by their distinctive melting temperature, which is a characteristic number.
The difference between freezing point and melting point:
- While a substance's melting point develops when it transforms from a solid to a liquid, a substance's freezing point happens when a liquid transforms into a solid when the heat from the substance is removed.
- When the temperature rises, the melting point can be seen, and when the temperature falls, the freezing point can be seen.
- When a solid reaches its melting point, its volume increases; meanwhile, when a liquid reaches its freezing point, its volume decreases.
- While a substance's freezing point is not thought of as a distinctive attribute, its melting point is.
- While external pressure is a significant component in freezing point, atmospheric pressure is a significant element in melting point.
- Heat must be supplied from an outside source in order to reach the melting point for such a state shift. When a material is at its freezing point, heat is needed to remove it from the substance in order to alter its condition.
<em>Reference: Berry, R. Stephen. "When the melting and freezing points are not the same." Scientific American 263.2 (1990): 68-75.</em>
