Explanation:
If you cannot visualize it, just assume that the distance from station A to B is 420km. Each half is 210km.
When the car travels from A to B, it takes 420/30 = 14 hours.
When the car travels from B to the halfway point, it takes 210/30 = 7 hours.
When the car travels from the halfway point to A, it takes 210/70 = 3 hours.
Total time taken = 14 + 7 + 3 = 24 hours.
Total distance = 420km * 2 = 840km.
Hence, the average speed of the car is 840/24 = 35km/h.
Sound waves travel faster through <em>solids</em> than they do through gases or liquids. <em>(C) </em>They don't travel through vacuum at all.
Example:
Speed of sound in normal air . . . around 340 m/s
Speed of sound in water . . . around 1,480 m/s
Speed of sound in iron . . . around 5,120 m/s
Answer:
Control of air–fuel ratio
Oxygen sensors tell the ECU whether the engine is running rich (too much fuel or too little oxygen) or running lean (too much oxygen or too little fuel) as compared to ideal conditions (known as stoichiometric).
Explanation:
About 80% of the earth's volume is made of mantle.
<span>The </span>mantle<span> is a layer inside a </span>terrestrial planet<span> and some other </span>rocky planetary bodies<span>. For a mantle to form, the planetary body must be large enough to have undergone the process of </span>planetary differentiation<span> by </span>density<span>. The mantle lies between the </span>core<span> below and the </span>crust<span> above. The terrestrial planets (</span>Earth<span>, </span>Venus<span>, </span>Mars<span> and </span>Mercury<span>), the </span>Moon<span>, two of </span>Jupiter<span>'s </span>moons<span> (</span>Io<span> and </span>Europa<span>) and the </span>asteroid Vesta<span> each have a mantle made of </span>silicate<span> rock.</span><span>Interpretation of spacecraft data suggests that at least two other moons of Jupiter (</span>Ganymede<span> and </span>Callisto<span>), as well as </span>Titan<span> and </span>Triton<span> each have a mantle made of </span>ice<span> or other </span>solid volatile<span> substances </span>up of Mantle
Hope this helped.
