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2 years ago

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Not yet answered Points out of 2.00 Not flaggedFlag question Question text Two cars collide head-on on a level friction-free roa

d. The collision was completely inelastic and both cars quickly came to rest during the collision. What is true about the velocity of this system's center of mass?

1 answer:

Natali5045456 [20]2 years ago

5 0

Answer:

Velocity of center of mass must be ZERO

Explanation:

As we know that two cars are moving on friction-less surface

So here we can say that on the system of cars there is no external force along x direction

So we can say that

$F_{net} = \frac{dP_{cm}}{dt}$

so here if net force is zero

$\frac{dP_{cm}}{dt} = 0$

$P_{cm} = constant$

since finally the two cars comes to rest so here final velocity of center of mass of two cars will be zero and hence it will be always zero as there is no force on the system of two cars

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Answer:

Explanation:

Given

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Final velocity = 4m/s

Distance S = 4000m

Required

Acceleration

Substitute the given parameters into the formula

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4² = 200²+2a(4000)

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a = -4.998m/s²

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2 years ago

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If you put it into English in the comments I would be more then happy to help you! Thank you!

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3 years ago

A car slows down uniformly from a speed of 30.0 m/s to rest in 7.20 s

Ede4ka [16]

When acceleration is constant, the average velocity is given by

$\bar v=\dfrac{v+v_0}2$

where $v$ and $v_0$ are the final and initial velocities, respectively. By definition, we also have that the average velocity is given by

$\bar v=\dfrac{\Delta x}{\Delta t}=\dfrac{x-x_0}{t-t_0}$

where $x,x_0$ are the final/initial displacements, and $t,t_0$ are the final/initial times, respectively.

Take the car's starting position to be at $t_0=0\,\mathrm s$ . Then

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So we have

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You also could have first found the acceleration using the equation

$v=v_0+at$

then solve for $x$ via

$x=x_0+v_0t+\dfrac12at^2$

but that would have involved a bit more work, and it turns out we didn't need to know the precise value of $a$ anyway.

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3 years ago

An unstable atomic nucleus has a mass of 17.010-27kg, and starts out at rest. When it decays, it the original nucleus disintegra

slega [8]

Answer:

Part a)

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Part b)

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Explanation:

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So we will have

$m_1v_1 + m_2v_2 + m_3v_3 = 0$

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Part b)

By equation of kinetic energy we have

$E = \frac{1}{2}m_1v_1^2 + \frac{1}{2}m_2v_2^2 + \frac{1}{2}m_3v_3^2$

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3 years ago

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Answer:

Check the explanation

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3 years ago