He conducted experiments in combining elements

Which option is an example of a physical property?

Lera25 [3.4K]

Answer:

it may be that last one

Explanation:

lol i may be incorrect:)

5 0

3 years ago

Mr. Arnold's 5th grade science class did an experiment to see if mold would grow better on moist bread or on dry bread. Each lab

Vladimir [108]

IT WOULD GROW BETTER ON MOIST BREAD BECAUSE IF IT IS DRIED IT IS HARDER FOR IT TO FORM AND IF IT IS MOIST IT WILL GET MOLD ON IT FASTER

3 0

3 years ago

A large rocket has a mass of 2.00×10⁶ kg at takeoff, and its engines produce a thrust of 3.50×10⁷ N. Find its initial accelerati

Kazeer [188]

Answer:

17.5 m/s²

1.90476 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

Force

$F=ma\\\Rightarrow a=\frac{F}{m}\\\Rightarrow a=\frac{3.5\times 10^7}{2\times 10^6}\\\Rightarrow a=17.5\ m/s^2$

Initial acceleration of the rocket is 17.5 m/s²

$v=u+at\\\Rightarrow \frac{120}{3.6}=0+17.5t\\\Rightarrow t=\frac{\frac{120}{3.6}}{17.5}=1.90476\ s$

Time taken by the rocket to reach 120 km/h is 1.90476 seconds

Change in the velocity of a rocket is given by the Tsiolkovsky rocket equation

$\Delta v=v_{e}\ln \frac{m_0}{m_f}$

where,

$m_0$ = Initial mass of rocket with fuel

$m_f$ = Final mass of rocket without fuel

$v_e$ = Exhaust gas velocity

Hence, the change in velocity increases as the mass decreases which changes the acceleration

4 0

3 years ago

A spring is compressed 8 cm. It is then brought back to equilibrium and compressed 24 cm. How much more work is done in the seco

posledela

Answer:

Nine times

Explanation:

$x_{i}$ = Initial compression of the spring = 8 cm = 0.08 m

$x_{f}$ = Final compression of the spring = 24 cm = 0.24 m

$k$ = Spring constant of the spring

Initial spring energy is given as

$U_{i} = (0.5) k x_{i}^{2}\\U_{i} = (0.5) k (8)^{2}\\U_{i} = 32 k$

Initial spring energy is given as

$U_{f} = (0.5) k x_{f}^{2}\\U_{f} = (0.5) k (24)^{2}\\U_{f} = 288 k = (9) (32) k = 9 U_{i}$

3 0

4 years ago

A heat recovery system (HRS) is used to conserve heat from the surroundings and supply it to the Mars Rover. The HRS fluid loop

Annette [7]

Answer: Volume of Freon = 12.23. $10^{3}$ L

Explanation: First, the temperatures have to be in the same unit, so all the tmeperatures is transformed into Kelvin:

T₁ = 192K

T₂ = $\frac{5}{9}$ . (F - 32)+273.15

T₂ = $\frac{5}{9}$ . (- 65 - 32)+273.15

T₂ = 219.26K.

Second, BTU is an unit of energy. It can be transformed into Joules by the relation 1BTU = 1055.06J.

Q = 1055.06 . 46.9 = 49482.314J

The letter Q represents Heat and is calculated as Q = m.Cp.ΔT, where:

m is mass of the element;

Cp is the heat capacity specific for each element;

ΔT is the difference between the final and initial temperature;

Third, it will be needed the properties of the Freon:

Freon (CF2Cl2) = 120.91g/mol; Cp = 74J/mol.K; ρ = 1.49kg/m³

Fourth, we calculate the mass of Freon necessary for the remove of 46.9BTU of energy from the system:

Q = m.Cp.ΔT

m= $\frac{Q}{c(T-T_{0} )}$

m = $\frac{49482.314}{74(219.26-192)}$

m = 18228.214g or m=18.228Kg

Fifth, using the density of Freon, Volume can be found

ρ = $\frac{m}{V}$

V = m / ρ

V = 18.228 / 1.49

V = 12.23m³

As SI for density is Kg/m³, the volume found is in m³.

Cubic meters is related to Liters as the following: 1m³=1000l.

So, volume of Freon = 12.23. $10^{3}$ L

The volume of Freon needed is 12.23. $10^{3}$ L.

7 0

3 years ago