you-jog-at-91-mathrmkm-mathrmh-for-50-mathrmkm-then-you-jump-into-a-car-and-drive-an-additional-13-m

Question

$. .$ You jog at 9.1 $\mathrm{km} / \mathrm{h}$ for 5.0 $\mathrm{km}$ , then you jump into a car and
drive an additional 13 $\mathrm{km}$ . With what average speed must you
drive your car if your average speed for the entire 18 $\mathrm{km}$ is to be
25 $\mathrm{km} / \mathrm{h}$ ?

Nathan Silvano · Accepted Answer

so in problem 16 we have a movement divided in two parts. The first part. We have a velocity of 9.1 kilometers per hour. Recover a distance of five. Hello, mentors. The second part, we drive in cover a distance of 13 kilometers. But we don&#x27;t have the velocity. No. So the problem wants to know the velocity of the second part, knowing that the total average velocity is going was 25 kilometers per hour. Well, we know how to calculate average velocity. So the average velocity of the second part is going to be they space week over in the second part, divided by the time we spent to cover this space. The problem is, we don&#x27;t have this time. So how we going to do to find this time? We can use the total time, then discovered it&#x27;s time for the second part. That&#x27;s CDs we know, thinking about home movement. We know that average velocity was 25. We know that the total space was 18. So the total time it&#x27;s going to be t course 18 divided by 25. This sissy quotes too suitable 0.7 two hours. Okay. And what was the time For the first part, we know the velocity we jog. We know the distance recover. So this time, for the first part, just going to be Oh, it&#x27;s C five divided by 9.1. This is it. Close to 0.55 hours. Okay, so what was the time For the second part? The time for the second part is just total time, minus the time for the first part. So this time for the second part is just zero point seven to minors. 0.55 That&#x27;s it&#x27;s close to 0.17 hours. Okay, well, we have the time for the second part so we can come back here and finish. The problem is just the average velocity is going to be 13 divided by 0.17. Let&#x27;s see if close to 76 0.4 kilometers per hour. That&#x27;s the final answer. Thank you for watching

Nicholas Majtenyi · Answer

question 29 states that a car mixing 100 kilometer trip it travels the 1st 50 kilometers at an average speed of 50 kilometers per hammer. How fast must travel the 2nd 50 kilometers. So as average speed is 100 kilometers per hour. Okay, so we can start this question off by noticing you want to find V two. So if you know, the average velocity we want is 100 comets traversing of the average. Desirable is 100 calories per hour. I can&#x27;t you use this situation to solve a beat too, so we can see that. Okay, well, an equation for V averages simply, you know, the total distance traveled over the total time were given D here we&#x27;ve given that total distance. However, we don&#x27;t have a total time it would take so we can find an expression for that. And then we can substitute back into here. So we know the total time it would take would be the time required for the first segment, which I&#x27;ll call t one. That&#x27;s the time it would require for the second segment using our relationship during distance velocity. In time, we can simply ordinate, reorganize This is D one over V one as the time for one second one Andy to over V two. Um, dealing with multiple fractions is not the most convenient. So if I multiply both terms of the first term by V two R b two and the one over everyone for the second term, this equation can be represented as a single fraction of V two d one. I was the one d two over the common denominator of you wanna v two. I just made a little more easy that I don&#x27;t have to keep writing multiple fractions every time. Great. So now that every expression have this expression, I can put it into my the average equation. So I put this up here, the average equals d, which we know now. And we&#x27;re dividing my tea so I could take the term we found here and inverted so eveyone over me, too. I mean, really, because we&#x27;re dividing my tea not just multiplied by t v two deep one plus the one D too. His expression, Um, one thing we can use is that note that d one equals means the same distances d two, and it&#x27;s equal to the half of the total distance, right? The whole trip is 100 kilometers. D one is half that so I can replace my denominator here the d again This for me to say I&#x27;m the one b two b to d one. It&#x27;s d or two because again, the one is also multiplied by D over too. So that means our distance terms cancel out and you put two and our didn&#x27;t enter numerator here you sound so it&#x27;s to be wanted me to over v two plus the one that whole tear equals b average, of course. But again, I did this all for me to hear I know what the average is So you little bit valid Eventually ranges equation survive the average most Why that by the tsunami nerd I hand side b two plus one and that equals to be one I need to. It is a couple more steps here. The average times V two plus the average times V one, minus two being one b two equal zero. I&#x27;m just doing this to get myself for making very obvious what I&#x27;m writing out and I collect my V two terms here. Ivy too who has B average minus two times V one collecting all my of the two terms thinking right on the opposite side of this. But that equals, um native. The average time&#x27;s the one which will come the naval command. Second, if I just do the following V two by both sides by my bracket terminal left. That&#x27;s the average times be one and I reorganized this denominator to be to be one minus b average. My native sign of the numerator goes away and now I have the average. I have the one so I can solve for this. However, generals in the denominator, Um well, I could use the top 100 kilometers per hour times. My velocity one is 50 kilometers per hour. However, her two times my initial velocity just 50 minus my average policy which is 100 notes. This expression here is zero. Therefore, if I divide 1/0, of course I get the limit of it goes to infinity. So therefore, because this is what&#x27;s beginning V two, it is not possible. There&#x27;s no possible speed for the second velocity in order to satisfy this requirement for an average velocity 100. Palmer&#x27;s so v to not possible would be appropriate. Not possible As long as again. You&#x27;re describing that this denominated term doesn&#x27;t go to zero, which means your value for view too would go to infinity.

Mayukh Banik · Answer

average velocity comes out to be a total distance traveled, which is everyone. Do you want us feed to Tito? Divided by the total time he want us stato? The speed for the first section is 10 in the middle part of our times. 1.5 hour. The US 15 either major party, Our times. 30 minute R, 0.5 hour divided by one point fight. Sit up or in five our. So that comes out of 10 times. What about five. 15? Thus 15 times half 7.5 divided by two He&#x27;s admitted by our 22.5 over. Two he&#x27;s admitted are our That comes out to be 11.25 kilometer by our

Shital Rijal · Answer

Okay, so we need to find the average speed. He says that the distance it covers in 10 minutes is a call to 10 kilometers. Now, this is not a sigh unit off distance. So converting this into meters by multiplying with 1000. This keeps me 10,000. Your readers. Right now, this is in meters so soon that the time chicken for Mr Stents is 10 minutes. Right? So that is equal to 600 seconds. So the every spell a city, he everything is equal to the total distance traveled up upon the triple time chicken. So that is it called too. 10,000 upon 600. And that comes out to be 16.67 meters for a second. All right, so this is the average velocity off that baker.

Josh Broderick Phillips · Answer

that we have a car which I&#x27;m just gonna draw the box that&#x27;s accelerating from rest. And it&#x27;s so its initial velocity is zero Ah, and its velocity at after 4.5 seconds is 95 kilometers per hour. Now I want to convert this kilometers per hour into meters per second. So the way I&#x27;m going to do that is some dimensional analysis kilometers, I&#x27;m gonna turn two meters, which is 1000 meters and one kilometer and then hours. I want one hour for H is Ah, 3600 seconds. And this would give me its check. Ages cancel uh, Kilometers, cancel on you get meters per second and this is actually approximately surrounded 26 point for war meters per second. And if I want to find this average acceleration and you Delta V over Delta T and Delta V is final velocity minus the initial velocity and l T is gonna be 0.5 minus zero. So this is around 26.4. Uh, but I&#x27;m gonna not round it until the end. So it&#x27;s like something, uh, minus zero over 4.5 minutes equals 5.9 meters per second squared

Himanshu Garg · Answer

We will solve this problem by converting the time for the dinner to complete the race in two seconds and then converting the distance of the rays from kilometers into meters. The Tennessee speed is the ratio off distance to time now. The conversion factors which will use here is one minute physical to 60 seconds and one kilometer is equal to 1000 m. The time to complete the race will be equal toe to 4 80 seconds. The distance off the race is 10 kilometer, which can be expressed as 1.0 multiplied by 10 to powerful meter. Therefore, average speed off runner in meter per second will be the distance covered, divided by the time taken in second, which is 4.3 m for second.

Problem

A dog runs back and forth between its two owners,…

Problem 16 Easy Difficulty

$. .$ You jog at 9.1 $\mathrm{km} / \mathrm{h}$ for 5.0 $\mathrm{km}$ , then you jump into a car and
drive an additional 13 $\mathrm{km}$ . With what average speed must you
drive your car if your average speed for the entire 18 $\mathrm{km}$ is to be
25 $\mathrm{km} / \mathrm{h}$ ?

Answer

$76.4 \mathrm{~km} / \mathrm{h}$

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