7) Which statement below best describes the motion of the cart under the conditions shown in the image below?

Magnet A doesn't have its poles labeled, but Magnet B has a clearly labeled north and south pole. If the

dusya [7]

Answer:

D: The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole

Explanation:

D: The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole because

1) opposite poles attract each other

2) similar poles repel each other

3)magnetic lines of force start at the north pole and end at the south pole

4 0

3 years ago

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The minimum frequency of light needed to eject electrons from a metal is called the threshold frequency, ν0. find the minimum en

shusha [124]

The energy carried by the incident light is
$E=hf$
where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
$E=hf=(6.63 \cdot 10^{-34}Js)(5.64 \cdot 10^{14}s^{-1})=3.74 \cdot 10^{-19}J$

4 0

4 years ago

Fill in a T/F answer for each statement below. If false, correct the statement to make it true.:

grandymaker [24]

Answer:

Explanation:

Let's answer these statements

.1) True. This is the law of reflection.

.2) False. The speed of light depends on the index of refraction n = c / v

v = c / n

.3) True. The frequency creates a forced oscillation, whereby the atoms re-emit at the same incident frequency

.4) False. The index of refraction is a measure of the ratio of the speed of light in a vacuum and the material environment, the ability to change the trajectory is given by the law of refraction

.5) True. True due to the change in beam trajectory due to the law of refraction

.6 False. The phenomenon occurs when you pass from a medium with a higher index to one with a lower ratio, because the refracted beam separates from the normal

.7) True.

.8) False so that the lightning approach is valid Lam >> d,

.9) True.

3 0

4 years ago

Katelyn (55 kg) is practicing a drop jump in the biomechanics lab. She steps off a plyometrics box, lands on the force plate, an

suter [353]

Answer:

J = 357.5 kg*m/s

Explanation:

The impulse exerted on Katelyn when she was on the force plate, is equal to the change in her momentum, according to Newton's 2nd Law.
Assuming as the positive direction the upward direction (coincident with the positive y-axis) we can express the initial momentum as follows:

$p_{o} = m*v_{o} = 55 kg * (-3.0 m/s) (1)$

By the same token, the final momentum is as follows:

$p_{f} = m*v_{f} = 55 kg * (3.5 m/s) (2)$

As we have already said, the impulse J is just equal to the change in momentum, i.e., the difference between (2) and (1):

$J = p_{f} - p_{o} = m* (v_{f} -v_{o}) = 55 kg* (3.5m/s- (-3.0m/s)) = 357.5 kg*m/s (3)$

5 0

3 years ago

In the graph, which region shows nonuniform positive acceleration?

cricket20 [7]

Answer: A.AB

Explanation:

This Velocity vs Time graph shows the acceleration of a body or object, since acceleration is the variation of velocity in time.

As we can see in the attached image, the graph can be divided in four segments:

OA: In this segment the acceleration is changing at a uniform rate. In addition we can see it has a positive slope, hence we are dealing with a positive uniform acceleration.

AB: In this segment the acceleration is changing at a nonuniform rate, since in this part it is not possible to calculate the slope. However if this were uniform, the slope woul be positive. This means the <u>acceleration is nonuniform and positive.</u>

BC: In this segment the acceleration is changing at a nonuniform rate, since in this part it is not possible to calculate the slope. However if this were uniform, the slope woul be negative. This means the acceleration is nonuniform and negative.

CD: In this segment the acceleration is changing at a uniform rate. In addition we can see it has a negative slope, hence we are dealing with a negative uniform acceleration.

From all these segments, the only one that fulfils the nonuniform positive acceleration condition is option A:

Segment AB

3 0

3 years ago

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