Answer: I added a picture of the answer
Explanation: its right
Answer:
3.9 seconds
Explanation:
Use constant acceleration equation:
y = y₀ + v₀ t + ½ at²
where y is the final position,
y₀ is the initial position,
v₀ is the initial velocity,
a is the acceleration,
and t is time.
Given:
y = 0 m
y₀ = 15 m
v₀ = 15 m/s
a = -9.8 m/s²
Substituting values:
0 = 15 + 15t + ½ (-9.8) t²
0 = 15 + 15t − 4.9t²
0 = 4.9t² − 15t − 15
Solve with quadratic formula:
t = [ -b ± √(b² − 4ac) ] / 2a
t = [ 15 ± √((-15)² − 4(4.9)(-15)) ] / 2(4.9)
t = [ 15 ± √(225 + 294) ] / 9.8
t = (15 ± √519) / 9.8
t = -0.79 or 3.9
It takes 3.9 seconds for the stone to reach the bottom of the well.
The negative answer is the time it takes the stone to travel from the bottom of the well up to the top of the well.
When the core runs out of hydrogen to fuse, then it starts fusing the helium. This happens because a star cannot create more hydrogen.
<span>There are various examples of land features formed by river erosion. One of them is Delta. A delta is formed when sediments are deposited in a place where a river flow into an ocean or lake and build up a land form. Thus, a river delta is a land form that occurs as a result of deposition of sediments carried by a river as the flow leaves its mouth and enter a slow moving or stagnant water.</span>
Answer:
Average speed of car will be 48 km/hr
Explanation:
Let the total distance is 2d
It is given that first half of the distance car travels with a speed of 40 km/hr
So time taken to cover half of the distance 
Second half of the distance is covered with a 60 km/hr
So time taken to cover second half of the distance 
So total time to cover 2d distance 
Average speed is the ratio of total distance to total time
So average speed 
So average speed of car will be 48 km/hr
