The answer would be D hope it helps and sorry if it is wrong. :)
Answer:
123 km/h
Explanation:
The distance between the Jeep Wrangler and the Ford Taurus is increasing.
Let us consider the north direction as positive when observing from the ground
So, the south direction will be negative
But when the observer is one of the cars the direction will be the same i.e., moving away from each other, so the velocity will be added.
Hence velocity of the Jeep relative to the Ford will be
Velocity of the Jeep + Velocity of the Ford
= 74+49 = 123 km/h
∴ Velocity of the Jeep relative to an observer in the Ford is 123 km/h
<span> Mass is a quantified value of how much matter is in you, while weight takes into account the effect of gravity. People will "weigh" less on the moon because of the lesser gravity, but they still have the same mass.</span>
Answer:
2. B
3. A
4. C
5. B
6. A
Explanation:
2. Sound waves use vibrating molecules to move. With this being said, sound waves would travel best through dense materials, and would travel worst in empty materials, like space. Using this information, you can infer that B would be the answer because water is denser than air and water is the densest material on that list.
3. The speed of the wave is equal to the frequency times the wavelength. Since it has a wavelength of 100 meter and 20 Hertz, the speed would 2000 m/s
4. Like noted in question 2, sound waves travel best in dense materials. Rock is the densest material in that last.
5. By looking at the chart, you can see that the speed increases by 4 m/s when the temperature increases by 10. Using simple division, you could determine that the speed would go up by 2 m/s since the jump between 15 degrees and 20 degrees is 5, which is half of 10, making the speed half of 4.
6. The speed would decrease because, like stated above, sound travels best through dense materials. Since rock is denser than air, the speed would decrease as it leaves.