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:
H₀ = 1.6 x 10⁻¹⁸ s⁻¹
Explanation:
The Hubble's Constant can be found by the following formula:
where,
H₀ = Hubble's Constant = ?
v = speed of galaxy = 30000 km/s = 3 x 10⁷ m/s
D = Distacance = 600 Mpc = (6 x 10⁸ pc)(3.086 x 10¹⁶ m/1 pc)
D = 18.52 x 10²⁴ m
Therefore,
<u>H₀ = 1.6 x 10⁻¹⁸ s⁻¹</u>
Answer:
1.a) 1 kJ
1.b) 4 kJ
ratio 1:4
1.c) 4 times as before
2.a) 3.33 m/s2
Explanation:
1.a) bicycle's velocity =Displacement/time
=100/20 m/s
=5 m/s
bicycler's KE =1/2 *mass*(velocity)^2
=1/2*80*5^2
=1000 J = 1 kJ
1.b) bicycle's new velocity =200/20 m/s
=10 m/s
bicycler's new KE =1/2*80*10^2
=4000 J = 4 kJ
Ratio= KE 1 :KE new
= 1 :4
1.c) when bicycler's speed was doubled it increased the KE by 4 times (2^2). because In KE we consider the square of the speed , so the factor we increase the speed , the KE will get increased with the square value of it
ex : speed is triple the prior value , then the KE is as 3^2 times as before. that is 9 times
2.a) car acceleration = (20-0)/6 m/s2
= 3.33 m/s2
Answer:
Check explanation
Explanation:
In the formation of calcium fluoride we take calcium and fluorine.
in elemental form calcium exist in solid form and fluorine in gaseous form.
formation of compound takes place to complete their octet, in case of calcium need to remove two electron and need to add one elecron in fluorine to complete their octet so two electron will ransferred from calcium to two fluorine atom.
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