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3 years ago

What is the minimum energy required to lift an object weighing 200 Newtons at a height of 20 meters?

Physics

1 answer:

lakkis [162]3 years ago

4 0

Work = force x distance

200 Newtons x 20 meters

= 4,000 Joules

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What is the difference between delta and harbor?

Margarita [4]

The difference between delta and harbor is is that delta is the fourth letter of the modern greek alphabet while harbor is a sheltered expanse of water, adjacent to land, in which ships may dock or anchor, especially for loading and unloading.

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4 years ago

A student lifts a physical science book off the table and above their head. Is there work being done?

DiKsa [7]

Answer: A force must cause a displacement in order for work to be done. A book falls off a table and free falls to the ground. Yes. This is an example of work.

Explanation:

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2 years ago

Air bags are designed to deploy in 10 ms. Given that the air bags expand 20 cm as they deploy, estimate the acceleration of the

joja [24]

As it is given that the air bag deploy in time

$t = 10 ms = 0.010 s$

total distance moved by the front face of the bag

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$d = v_i*t + \frac{1}{2}at^2$

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$g = 10 m/s^2$

so we have

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3 years ago

An elevator is moving down with an acceleration of 3.36 m/s2.

sergeinik [125]

Answer : 413.44N

Here it is given that an elevator is moving down with an acceleration of 3.36 m/s² . And we are interested in finding out the apparent weight of a 64.2 kg man . For the diagram refer to the attachment .

From the elevator's frame ( non inertial frame of reference) , we would have to think of a pseudo force.
The direction of this force is opposite to the direction of acceleration the frame and its magnitude is equal to the product of mass of the concerned body with the acceleration of the frame .
When a elevator accelerates down , the weight recorded is less than the actual weight .

From the Free body diagram ,

$\sf\longrightarrow Weight = mg - ma \\$

$\sf\longrightarrow Weight = m ( g - a ) \\$

Mass of the man = 64.2 kg

$\sf\longrightarrow Weight = 64.2( 9.8 - 3.36) N\\$

$\sf\longrightarrow Weight = 64.2 * 6.44 N\\$

$\sf\longrightarrow \underline{\boxed{\bf Weight_{apparent}= 413.44 N }} \\$

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2 years ago

If the frequency of the incoming light is increased, will the energy of the ejected electrons increase, decrease, or stay the sa

Arlecino [84]

Answer:

increase

Explanation:

According to Einstein's photoelectric equation; the energy of a photon striking a metal surface is related to the kinetic energy of the ejected photoelectron by the formula;

KE= hf - hfo

Where h is the planks constant, f and fo refer to the frequency of incident photon and the threshold frequency respectively.

Hence, we can clearly see from the foregoing that the kinetic energy of the ejected photoelectron is proportional to the frequency of the incident photon.

Hence, if the frequency of the incident photon is increased, the kinetic energy of the ejected photoelectron increases also.

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3 years ago