At its maximum height h, the football has zero vertical velocity, so if it was kicked with initial upward speed v, then
0² - v² = -2gh
Solve this for v :
v² = 2gh
v = √(2gh)
The height y of the football t seconds after being kicked is
y = vt - 1/2 gt²
Substitute v = √(2gh), replace y = h, and solve for h when t = 3.8 s :
h = √(2gh) t - 1/2 gt²
h = √(2gh) (3.8 s) - 1/2 g (3.8 s)²
h ≈ (16.8233 √m) √h - 70.756 m
(By √m, I mean "square root meters"; on its own this quantity doesn't make much physical sense, but we need this to be consistent with √h. h is measured in meters, so √h is measured in √m, too.)
h - (16.8233 √m) √h + 70.756 m = 0
Use the quadratic formula to solve for √h :
√h = ((16.8233 √m) ± √((16.8233 √m)² - 4 (70.756 m))) / 2
Both the positive and negative square roots result in the same solution,
√h ≈ 8.411 √m
Take the square of both sides to solve for h itself:
(√h)² ≈ (8.411 √m)²
⇒ h ≈ 70.756 m ≈ 71 m
The kinetic energy increases 4 times
1). trajectory
2). person sitting in a chair
3). 490 meters
4). 65 m/s
5). False. The projectile's displacement, velocity, and acceleration have vertical and horizontal components, but the projectile doesn't.
6). False
7). The vertical component of a projectile doesn't change due to gravity, but the vertical components of its displacement, velocity, and acceleration do.
The vertical components do NOT equal the horizontal components.
8). Decreasing if you include the effects of air resistance. Constant if you don't. Gravity has no effect on horizontal velocity.
9). We can't see the simulation. But if the projectile doesn't have jets on it, then as it travels upward, its vertical velocity must decrease, because gravity is trying to not let it get away.
10). We can't see the simulation. But if the projectile is traveling downward, we would call that "falling", and its vertical velocity must increase, because gravity is pulling it downward.
The average speed will be 2.38×10⁶ m/sec.The average speed of an object indicates the pace at which it will traverse a distance. The metric unit of speed is the meter per second.
<h3>What is the average speed?</h3>
The total distance traveled by an object divided by the total time taken is the average speed.
The speed calculated at any particular instant of time is known as the instantaneous speed.
Given data;
Distance travelled = 4.12x10¹⁶ meter
Time period= 1.73x10¹⁰ sec
The average speed is found as
Hence, the average speed will be 2.38×10⁶ m/sec.
To learn more about the average speed, refer to the link;
brainly.com/question/12322912
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