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2 years ago

Can someone explain it with steps?

Physics

2 answers:

Yakvenalex [24]2 years ago

8 0

Initial velocity=15m/s=u
Final velocity=0
deacceleration=a

Distance traveled during reaction time

15(0.4)=6m

Total distance

21-6-1=14m

$\\ \sf\longmapsto v^2-u^2=2as$

$\\ \sf\longmapsto -(15)^2=2(14)a$

$\\ \sf\longmapsto -225=28a$

$\\ \sf\longmapsto a=-8.0m/s^2$

Anton [14]2 years ago

5 0

Answer:

Option C is the correct answer

Explanation:

Distance travelled by car during reaction time

$=15\times0.4\\\\=6m$

The car stopped before hitting the animal by $1 m$

Distance travelled during deceleration is $21-6-1=14m$

Hence by $v^2=u^2+2as$

We have

$0^2=15^2+2 \cdot a \cdot 14\\\\a=\frac{-225}{28} \\\\=-8.03m/s^2$

Option C is the correct answer

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A 250. mL sample of gas at 1.00 atm and 20.0°C has the temperature increased to 40.0°C and the volume increased to 500. mL. What

ladessa [460]

Answer:

New pressure is 0.534 atm

Explanation:

Given:

Initial volume of the gas, V₁ = 250 mL

Initial pressure of the gas, P₁ = 1.00 atm

Initial temperature of the gas, T₁ = 20° C = 293 K

Final volume of the gas, V₂ = 500 mL

Final pressure of the gas = P₂

Final temperature of the gas, T₁ = 40° C = 313 K

now,

we know for a gas

PV = nRT

where,

n is the moles

R is the ideal gas constant

also, for a constant gas

we have

(P₁V₁/T₁) = (P₂V₂/T₂)

on substituting the values in the above equation, we get

(1.00 × 250)/293 = (P₂ × 500)/313

P₂ = 0.534 atm

Hence, the new pressure is 0.534 atm

5 0

3 years ago

¿Cuál es la masa de un objeto cuya masa es de 400 J y energía cinética de 107J?

Pachacha [2.7K]

Answer:

Mass, m = 125 kg

Explanation:

Let us assume that the question says, "What is the mass of an object whose velocity is 400 m/s and the kinetic energy of 10⁷ J.

The kinetic energy of an object is :

$K=\dfrac{1}{2}mv^2\\\\m=\dfrac{2K}{v^2}\\\\m=\dfrac{2\times 10^7}{(400)^2}\\\\m=125\ kg$

So, the mass of the object is 125 kg.

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3 years ago

What would be the current of the same wire if it was moved up towards the magnet instead of through the magnetic field?

Aleks04 [339]

Answer:

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Explanation:

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2 years ago

A spherical balloon is made from a material whose mass is 3.30 kg. The thickness of the material is negligible compared to the 1

stellarik [79]

Answer:

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Explanation:

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v = Volume of balloon = $\frac{4}{3}\pi r^3$

M = Molar mass of helium = $4.0026\times 10^{-3}\ kg/mol$

$\rho$ = Density of surrounding air = $1.19\ kg/m^3$

R = Gas constant = 8.314 J/mol K

T = Temperature = 345 K

Weight of balloon + Weight of helium = Weight of air displaced

$mg+m_{He}g=\rho vg\\\Rightarrow m_{He}=\rho vg-m\\\Rightarrow m_{He}=1.19\times \frac{4}{3}\pi 1.25^3-3.3\\\Rightarrow m_{He}=6.4356\ kg$

Mass of helium is 6.4356 kg

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Ideal gas law

$P=\frac{nRT}{v}\\\Rightarrow P=\frac{1607.85489\times 8.314\times 345}{\frac{4}{3}\pi 1.25^3}\\\Rightarrow P=563712.04903\ Pa$

The absolute pressure of the Helium gas is 563712.04903 Pa

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2 years ago

What is Newton's Second Law of Motion? (2 points) Every reaction is equal to the force applied. Forces are balanced when they ar

raketka [301]

Well, they're not quite the way Newton expressed it, but out of all this mess of statements, there are two that are correct AND come from Newton's 2nd Law of Motion:

-- The smaller the mass of an object, the greater the acceleration of that object when a force is applied.

-- The greater the force applied, the greater the acceleration.

For the other statements in the question:

-- Every reaction is equal to the force applied. True; comes from Newton's 3rd law of motion.

-- Forces are balanced when they are equal and opposite. True; kind of a definition, not from Newton's laws of motion.

-- An object at rest or in motion will remain at rest or in motion unless acted upon by an unbalanced force. True; comes from Newton's 1st law of motion.

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2 years ago