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3 years ago

A kangaroo has a maximum gravitational potential energy during one jump of 770 J

Physics

1 answer:

KengaRu [80]3 years ago

5 0

Answer:

k = 44000 N/m

Explanation:

Given the following data;

Maximum gravitational potential energy = 770 J

Elastic potential energy = 14% of 770 J = 14/100 * 770 = 107.8 J

Extension, x = 42 - 35 = 7cm to meters = 7/100 = 0.07 m

To find the spring constant, k;

The elastic potential energy of an object is given by the formula;

$E.P.E = \frac {1}{2}kx^{2}$

Substituting into the equation, we have;

$107.8 = \frac {1}{2}*k*0.07^{2}$

$107.8 = \frac {1}{2}*k*0.0049$

Cross-multiplying, we have;

$215.6 = k*0.0049$

$k = \frac {215.6}{0.0049}$

k = 44000 N/m

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A small mailbag is released from a helicopter that is descending steadily at 3 m/s.

mario62 [17]

<u>Answer:</u>

a) Speed of mailbag after 3 seconds = 32.4 m/s

b) Package is 44.1 meter below helicopter

c) If the helicopter was rising steadily at 3.00 m/s

Speed of mailbag after 3 seconds = 26.4 m/s

Package is 44.1 meter below helicopter

<u>Explanation:</u>

a) We have equation of motion, v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.

Initial velocity = 3 m/s, acceleration = 9.8 $m/s^2$ and time = 3 seconds.

v = 3+9.8*3 = 32.4 m/s

Speed of mailbag after 3 seconds = 32.4 m/s

b) We have equation of motion , $s= ut+\frac{1}{2} at^2$ , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

Velocity of helicopter = 3 m/s, time taken = 3 seconds, acceleration = 0 $m/s^2$ .

$s= 3*3+\frac{1}{2} *0*3^2\\ \\ s=9m$

Distance traveled by helicopter = 9 meter.

Velocity of package = 3 m/s, time taken = 3 seconds, acceleration = 9.8 $m/s^2$ .

$s= 3*3+\frac{1}{2} *9.8*3^2\\ \\ s= 53.1m$

Distance traveled by package = 53.1 meter.

So package is (53.1-9)meter below helicopter = 44.1 m

c) Initial velocity = -3 m/s, acceleration = 9.8 $m/s^2$ and time = 3 seconds.

v = -3+9.8*3 = 26.4 m/s

Speed of mailbag after 3 seconds = 26.4 m/s

Velocity of helicopter = -3 m/s, time taken = 3 seconds, acceleration = 0 $m/s^2$ .

$s= -3*3+\frac{1}{2} *0*3^2\\ \\ s=-9m$

Distance traveled by helicopter = 9 meter.

Velocity of package = -3 m/s, time taken = 3 seconds, acceleration = 9.8 $m/s^2$ .

$s= -3*3+\frac{1}{2} *9.8*3^2\\ \\ s= 35.1m$

Distance traveled by package = 35.1 meter.

So package is (35.1+9)meter below helicopter = 44.1 m

4 0

4 years ago

The Big Bang is considered a scientific theory. Why is this true?

Kitty [74]

Answer:

Explanation:In the natural sciences we make observations and construct models.

If those models are consistent with our observations then we can make predictions from those models and test them against more observations.

If some observations contradict our models, then we can tell that our models are wrong or in need of modification.

For example, Newton's laws of physics provide pretty good models sufficient in accuracy to allow us to calculate how to land a man on the moon. Are they therefore true? Not exactly. Newton's laws fail to work well at velocities approaching the speed of light. So we can tell that they need some adjustment.

Einstein's special and general theory of relativity provide more accurate models. So are they true? They predict all sorts of strange behaviour which we have actually observed. They seem to provide useful models, but they do not explain everything. For example, the extreme conditions in a black hole or those we think existed at the start of the universe provide some challenges to General Relativity.

From a practical perspective it is useful to operate within theoretical frameworks that we treat as facts. We need to make assumptions in order to reach substantial conclusions. So we often act as if something like Big Bang theory is a fact, but we cannot know it to be so.

Essentially in any natural science we cannot prove anything to be true. We can demonstrate that theories are false. This is the honesty of science.

Consider an alternative theory: The universe and everything you "know" actually started

minutes ago.

You may protest that you remember what you did yesterday. In my theory I can explain that these are simply implanted memories, not real. What about radiometric dating? What about the Andromedra galaxy being

2.5

million light years away, so the light we see from it started travelling in our direction

2.5

million years ago? In my theory I can claim that these are all an elaborate implanted fiction.

There is no way to prove that this theory is true and probably no way to prove that it is false.

5 0

4 years ago

Facts about Tsunami?

Zepler [3.9K]

1.A tsunami is a series of ocean waves caused by an underwater earthquake, landslide, or volcanic eruption. More rarely, a tsunami can be generated by a giant meteor impact with the ocean. These waves can reach heights of over 100 ft.
2.About 80% of tsunamis happen within the Pacific Ocean’s “Ring of Fire.”
3.The first wave of a tsunami is usually not the strongest, successive waves get bigger and stronger.
4.Tsunamis can travel at speeds of about 500 miles or 805 kilometers an hour, almost as fast as a jet plane.
5.The states in the U.S. at greatest risk for tsunamis are Hawaii, Alaska, Washington, Oregon, and California.
Hope it help!

4 0

4 years ago

The manufacturer of a 6 V dry-cell flashlight battery says that the battery will deliver 15 mA for 64 continuous hours. During t

Misha Larkins [42]

Answer:

E =17,280 J

Explanation:

Since the voltage drops linearly from 6V to 4V, the average is 5V. The energy delivered is .

V is the average of initial and fianl voltage

A is the current passing

t is the time in which current is passed

E=V*A*t = 5*0.015*(64*3600) = 17,280 J

6 0

3 years ago

I Need Help With This

timama [110]

use the equations provided it shouldn't he hard

5 0

3 years ago

Read 2 more answers