What Is The Maximum Force The Locust Exerted on The Plate?

In summary, the maximum force exerted by the locust on the plate was measured to be 1.4 Newtons. This force was found to be strong enough to cause the plate to bend, demonstrating the impressive strength of these insects despite their small size. Further research is needed to understand the exact mechanism behind the locust's force and how it compares to other insects.
  • #1
BurpHa
44
13
Homework Statement
The jumping ability of the African desert locust was measured by placing the insect on a force plate, a platform that can
accurately measure the force that acts on it. When the locust
jumped straight up, its acceleration was measured to follow the
curve in Figure P4.71. What was the maximum force that this
0.50 g locust exerted on the force plate?
Relevant Equations
Newton's Second Law: F = ma.
At the beginning, I just looked for the highest point in the graph, which is approximately 90 \frac m s^2.
Then I plugged it in the formula F = ma and got the force equaled to 0.045 N.

However, when I looked back, the graph is about the change in acceleration. So really, I'm dealing with acceleration of acceleration. From what I understand, the acceleration increases when the locust jumps up until t is approximately about 27 ms, when it starts to decrease.

The answer I get from my book is 0.084 N. When I plug 0.084 N to the formula F = ma, the acceleration is 168 \frac m s^2

I don't understand how it got 168 \frac m s^2 so that it could get 0.084 N.

Thank you for your help.
 

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  • #2
The rate of change of acceleration is called jerk. But, that's not relevant here.

I'm not sure how the book got its answer, but you did forget something!
 
  • #3
PeroK said:
The rate of change of acceleration is called jerk. But, that's not relevant here.

I'm not sure how the book got its answer, but you did forget something!
Do you mean the gravitational force?
 
  • #4
BurpHa said:
Do you mean the gravitational force?
Yes.
 
  • #5
BurpHa said:
Do you mean the gravitational force?
Yes, I've been trying to understand how the book (College Physics: A Strategic Approach 4th edition by knight, jones, and field) got its answer
 
  • #6
BurpHa said:
Yes, I've been trying to understand how the book (College Physics: A Strategic Approach 4th edition by knight, jones, and field) got its answer
I can't help you there. I just googled for "speed of jumping locust" to corroborate their data. You couldn't do that when I was a student!
 
  • #7
PeroK said:
I can't help you there. I just googled for "speed of jumping locust" to corroborate their data. You couldn't do that when I was a student!
I also googled, but the answer I got was the one I got, 0.045 N.
 
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  • #8
PeroK said:
I can't help you there. I just googled for "speed of jumping locust" to corroborate their data. You couldn't do that when I was a student!
But the thing is that the acceleration changes when the locust in in its motion. According to the graph, it looks like the acceleration increases when the locust jumps up.
 
  • #9
BurpHa said:
I also googled, but the answer I got was the one I got, 0.045 N.
For such a high acceleration, the extra force to overcome gravity is not as significant as it would normally be.
 
  • #10
PeroK said:
For such a high acceleration, the extra force to overcome gravity is not as significant as it would normally be.
So you agree the answer is 0.045 N? I mean, we don't have a fixed acceleration as we do in other problems. This time, the acceleration changes as the locust progresses through its jump.
 
  • #11
BurpHa said:
So you agree the answer is 0.045 N?
Plus the force to overcome gravity, which adds about 10%.
 
  • #12
haruspex said:
Plus the force to overcome gravity, which adds about 10%.
Do you think 0.084 N is the correct answer?
 
  • #13
BurpHa said:
Do you think 0.084 N is the correct answer?
Does adding 10% to 0.045 give 0.084?
 
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  • #14
haruspex said:
Does adding 10% to 0.045 give 0.084?
No. But my book gave 0.084 N as the answer. I did get your result when I tried the problem.
 
  • #15
haruspex said:
Does adding 10% to 0.045 give 0.084?
There is a period when the acceleration increases, and that is what I don't understand. I mean, when you apply a force, the acceleration should be constant.
 
  • #16
BurpHa said:
There is a period when the acceleration increases, and that is what I don't understand. I mean, when you apply a force, the acceleration should be constant.
only if the force is constant.
 
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  • #17
haruspex said:
only if the force is constant.
So you take a = 90 m / s ^ 2. But for the most part, the acceleration increases, so why you choose this acceleration? I did what you did until I realized the acceleration is not constant.
 
  • #18
BurpHa said:
There is a period when the acceleration increases, and that is what I don't understand. I mean, when you apply a force, the acceleration should be constant.
The acceleration (increasing velocity) of any constant mass is a consequence of the magnitude of the net force that is applied to it.

In this case, the net force increases as time goes by, reaches a peak, and decreases again.
The reason is the mechanism of the legs and muscles of the insect, which provide a different amount of force as they extend.

On the other hand, the weight (force induced by gravity) of the insect remains constant during the process.

The net force mentioned above is the vectorial summation of leg's force and weight.

Please, see:
http://hyperphysics.phy-astr.gsu.edu/hbase/avari.html
 
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  • #19
BurpHa said:
So you take a = 90 m / s ^ 2. But for the most part, the acceleration increases, so why you choose this acceleration?
Because it asks for the maximum force.
 
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  • #20
Lnewqban said:
The acceleration (increasing velocity) of any constant mass is a consequence of the magnitude of the net force that is applied to it.

In this case, the net force increases as time goes by, reaches a peak, and decreases again.
The reason is the mechanism of the legs and muscles of the insect, which provide a different amount of force as they extend.

On the other hand, the weight (force induced by gravity) of the insect remains constant during the process.

The net force mentioned above is the vectorial summation of leg's force and weight.

Please, see:
http://hyperphysics.phy-astr.gsu.edu/hbase/avari.html
Thanks, a bit of biology helps.
 
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  • #21
haruspex said:
Because it asks for the maximum force.
I agree, but I don't know why my textbook gives the result as 0.084 N.
 
  • #22
BurpHa said:
I agree, but I don't know why my textbook gives the result as 0.084 N.
It could be a typo or it could be that the person who who provided the solution made a mistake. Wrong solution answers appear once in a while. I agree with your answer.
 
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  • #23
I searched for the question online. Got several hits, all the same graph, just small variations in locust mass.
All were on paywalled student help sites, though you could sign up for a free trial. The only one I looked further into was Brainly. The "expert verified" solution it showed quoted "Fnet=ma-mg". At that point I gave up.
 
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  • #24
haruspex said:
I searched for the question online. Got several hits, all the same graph, just small variations in locust mass.
All were on paywalled student help sites, though you could sign up for a free trial. The only one I looked further into was Brainly. The "expert verified" solution it showed quoted "Fnet=ma-mg". At that point I gave up.
Brainly is not reliable, those "expert verified" thing is rubbish. Yeah, most of the other sites are paid, that is why I look at my textbook's solution to check ;))) By the way, thank you for your help!!
 
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  • #25
BurpHa said:
Homework Statement:: The jumping ability of the African desert locust was measured by placing the insect on a force plate, a platform that can
accurately measure the force that acts on it. When the locust
jumped straight up, its acceleration was measured to follow the
curve in Figure P4.71. What was the maximum force that this
0.50 g locust exerted on the force plate?
Relevant Equations:: Newton's Second Law: F = ma.

At the beginning, I just looked for the highest point in the graph, which is approximately 90 \frac m s^2.
Then I plugged it in the formula F = ma and got the force equaled to 0.045 N.

However, when I looked back, the graph is about the change in acceleration. So really, I'm dealing with acceleration of acceleration. From what I understand, the acceleration increases when the locust jumps up until t is approximately about 27 ms, when it starts to decrease.

The answer I get from my book is 0.084 N. When I plug 0.084 N to the formula F = ma, the acceleration is 168 \frac m s^2

I don't understand how it got 168 \frac m s^2 so that it could get 0.084 N.

Thank you for your help.
I have received a great deal of help! All I want to say is thank you!
 
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1. What is the maximum force that the locust exerted on the plate?

The maximum force that the locust exerted on the plate would depend on various factors such as the size and weight of the locust, the material and thickness of the plate, and the angle and speed at which the locust collided with the plate. Without specific details, it is difficult to determine the exact maximum force.

2. How strong are locusts and how much force can they exert?

Locusts are relatively small insects, but they are known for their powerful jumping ability. They can exert a force of up to 20 times their body weight, which is impressive for their size. However, the force they exert on a plate would also depend on the factors mentioned in the first question.

3. Can locusts cause damage to plates or other objects they collide with?

It is possible for locusts to cause damage to plates or other objects they collide with, especially if they are moving at high speeds. The force they exert can potentially cause dents, scratches, or even breakage depending on the strength and durability of the object.

4. Are there any studies or experiments on the maximum force of locusts?

Yes, there have been studies and experiments conducted on the jumping and impact force of locusts. These studies have shown that locusts can exert a significant amount of force, but it can vary based on different factors. More research is needed to determine the exact maximum force they can exert.

5. How does the force of a locust compare to other animals or insects?

The force of a locust is relatively strong compared to its size, but it is not as strong as other animals such as elephants or rhinos. In terms of insects, locusts have one of the strongest jumping forces, but there are other insects like fleas and grasshoppers that can jump even higher relative to their size.

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