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3 years ago

Which of the following has a negative acceleration?

Physics

1 answer:

Volgvan3 years ago

6 0

Answer:

B. A car sits at rest at a stop sign.

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The soccer game begins with a ______ ______ in the center of the field

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It begins with a kick-off

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3 years ago

If two monochromatic light waves undergo destructive interference, the amplitude of the resultant wave is

lesya692 [45]

Answer: The amplitude is 0. (assuming that the amplitude ot both initial waves is the same)

Explanation:

When two monochromatic light waves of the same wavelength and same amplitude undergo destructive interference, means that the peak of one of the waves coincides with the trough of the other, so the waves "cancel" each other in that point in space.

Then if two light waves undergo destructive interference, the amplitude of the resultant wave in that particular point is 0.

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3 years ago

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Jenny loves puffed rice cereal. As she is pouring the cereal, two little

Ede4ka [16]

Answer:

4.9 x 10-23 N

Explanation:

I took the test

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3 years ago

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Consider a father pushing a child on a playground merry-go-round. The system has a moment of inertia of 84.4 kg.m^2. The father

Sophie [7]

Answer:

Explanation:

Given that:

the initial angular velocity $\omega_o = 0$

angular acceleration $\alpha$ = 4.44 rad/s²

Using the formula:

$\omega = \omega_o+ \alpha t$

Making t the subject of the formula:

$t= \dfrac{\omega- \omega_o}{ \alpha }$

where;

$\omega = 1.53 \ rad/s^2$

∴

$t= \dfrac{1.53-0}{4.44 }$

t = 0.345 s

Using the formula:

$\omega ^2 = \omega _o^2 + 2 \alpha \theta$

here;

$\theta$ = angular displacement

∴

$\theta = \dfrac{\omega^2 - \omega_o^2}{2 \alpha }$

$\theta = \dfrac{(1.53)^2 -0^2}{2 (4.44) }$

$\theta =0.264 \ rad$

Recall that:

2π rad = 1 revolution

Then;

0.264 rad = (x) revolution

$x = \dfrac{0.264 \times 1}{2 \pi}$

x = 0.042 revolutions

Here; force = 270 N

radius = 1.20 m

The torque = F * r

$\tau = 270 \times 1.20 \\ \\ \tau = 324 \ Nm$

However;

From the moment of inertia;

$Torque( \tau) = I \alpha \\ \\ Since( I \alpha) = 324 \ Nm. \\ \\ Then; \\ \\ \alpha= \dfrac{324}{I}$

given that;

I = 84.4 kg.m²

$\alpha= \dfrac{324}{84.4} \\ \\ \alpha=3.84 \ rad/s^2$

For re-tardation; $\alpha=-3.84 \ rad/s^2$

Using the equation

$t= \dfrac{\omega- \omega_o}{ \alpha }$

$t= \dfrac{0-1.53}{ -3.84 }$

$t= \dfrac{1.53}{ 3.84 }$

t = 0.398s

The required time it takes= 0.398s

5 0

2 years ago

How much force is needed to stop a body of mass 10kg

almond37 [142]

Answer:

Force of 100 N will be needed.

Explanation:

$Force, F = m \times g$

g is acceleration due to gravity

m is the mass

$F = (10 \times 10) \\ F = 100 \: newtons$

3 0

2 years ago

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