Answer:
The time he can wait to pull the cord is 41.3 s
Explanation:
The equation for the height of the skydiver at a time "t" is as follows:
y = y0 + v0 · t + 1/2 · g · t²
Where:
y = height at time "t".
y0 = initial height.
v0 = initial velocity.
t = time.
g = acceleration due to gravity (-9.8 m/s² considering the upward direction as positive).
First, let´s calculate how much time will it take for the skydiver to hit the ground if he doesn´t activate the parachute.
When he reaches the ground, the height will be 0 (placing the origin of the frame of reference on the ground). Then:
y = y0 + v0 · t + 1/2 · g · t²
0 m = 15000 m + 0 m/s · t - 1/2 · 9.8 m/s² · t²
0 m = 15000 m - 4.9 m/s² · t²
-15000 m / -4.9 m/s² = t²
t = 55.3 s
Then, if it takes 4.0 s for the parachute to be fully deployed and the parachute has to be fully deployed 10.0 s before reaching the ground, the skydiver has to pull the cord 14.0 s before reaching the ground. Then, the time he can wait before pulling the cord is (55.3 s - 14.0 s) 41.3 s.
We need it to calculate the how big it is, it’s mass, or even volume to get the measurements of lots of objects
Answer:
high density can withstand high acceleration and applied forces
Heavy metals are toxic to humans,
the clay is quite abundant and in general it is not toxic
Explanation:
The selection of materials for the construction of rockets takes into account many aspects, the technical resistance to the demands of space travel, but also the abundance of the material. Heavy metals have two very serious problems. The first one, some of them are a little scarce in nature, but the most serious problem is that almost all of them are toxic to humans, for example: lead and mercury.
On the other hand, the clay is quite abundant and in general it is not toxic to living beings.
If we use Newton's second law
F = m a
let's use the concept of density
rho = m / V
m = rho V
let's substitute
F = rho V a
From this expression we see that a material with high density can withstand high acceleration and applied forces, such as those existing in spacecraft clearance and re-entry to Earth.
Unfortunately with this law there is no criterion to select a material unless its density is high, in addition to this criterion low toxicity criteria for human beings are used,
Answer:
Pluto & Mercury
Explanation:
Pluto's eccentricity is 0.248
Mercury's eccentricity is 0.206
