Answer:
S = 11.025 m
Explanation:
Given,
The time taken by the pebble to hit the water surface is, t = 1.5 s
Acceleration due to gravity, g = 9.8 m/s²
Using the II equations of motion
S = ut + 1/2 gt²
Here u is the initial velocity of the pebble. Since it is free-fall, the initial velocity
u = 0
Therefore, the equation becomes
S = 1/2 gt²
Substituting the given values in the above equation
S = 0.5 x 9.8 x 1.5²
= 11.025 m
Hence, the distance from the edge of the well to the water's surface is, S = 11.025 m
The average velocity of the car for the whole journey is 69.57 km/h.
The given parameters:
- <em>Length of the road, L = 320 km</em>
- <em>Distance covered = 240 km at 75 km/h</em>
- <em>time spent refueling, t₂ = 0.6 hr</em>
- <em>Final velocity, = 100 km/hr</em>
The time spent by the before refueling is calculated as follows;
![t = \frac{d}{v} \\\\t_1 = \frac{240}{75} \\\\t_1 = 3.2 \ hours](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7Bd%7D%7Bv%7D%20%5C%5C%5C%5Ct_1%20%3D%20%5Cfrac%7B240%7D%7B75%7D%20%5C%5C%5C%5Ct_1%20%3D%203.2%20%5C%20hours)
The time spent by the car for the remaining journey;
![t_3 = \frac{320 - 240}{100} \\\\t_3 = 0.8 \ hr](https://tex.z-dn.net/?f=t_3%20%3D%20%5Cfrac%7B320%20-%20240%7D%7B100%7D%20%5C%5C%5C%5Ct_3%20%3D%200.8%20%5C%20hr)
The total time of the journey is calculated as follows;
![t = t_1 + t_2 + t_3\\\\t = 3.2 \ hr \ + \ 0.6 \ hr \ + \ 0.8 \ hr\\\\t = 4.6 \ hours](https://tex.z-dn.net/?f=t%20%3D%20t_1%20%2B%20t_2%20%2B%20t_3%5C%5C%5C%5Ct%20%3D%203.2%20%5C%20hr%20%5C%20%2B%20%5C%200.6%20%5C%20hr%20%5C%20%2B%20%5C%200.8%20%5C%20hr%5C%5C%5C%5Ct%20%3D%204.6%20%5C%20hours)
The average velocity of the car for the whole journey is calculated as follows;
![v = \frac{total \ distance }{total \ time} \\\\v = \frac{320}{4.6} \\\\v = 69.57 \ km/h](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7Btotal%20%5C%20distance%20%7D%7Btotal%20%5C%20time%7D%20%5C%5C%5C%5Cv%20%3D%20%5Cfrac%7B320%7D%7B4.6%7D%20%5C%5C%5C%5Cv%20%3D%2069.57%20%5C%20km%2Fh)
Learn more about average velocity here: brainly.com/question/6504879
Answer: D
Explanation: there is less light at that point.