Help with hard Standard Form questions?

I only expect a few answers, as this is very high level maths. Those of you that CAN work this stuff out, please could you show your workings out as I need it for school. I would do it myself but I was ill the entire time we did this subject and my teacher is very strict. T H A N K Y O U to whoever can give me any answers :D

1)A bullet travels at 1.35*10^3 m/s. The Duck is about 5.5*10^5 away. If I wanted to shoot Ali who was standing behind the Duck, how long would it take the bullet to get there? Answer in 3 Significant Figures.

2) In Mexico they produce around 2 103 360 000 kg of Taco's every year. How many banana's do they produce in 5 Years? (In standard Form, obviously.

3)Scientists have discovered an inhabitable planet 40 Light Years away. Given that 1 light year is 9.4605284*10^15 metres, how far is 40 light years in km? Standard form answer!

4) If the area of Australia is 7.692*10^6 km^2, what is that in square centimetres? Again, standard form answers.

5) The radius of the sun is 6.96*10^8m. What is the total surface area of the sun to 3.s.f? It's a sphere/ TSA of a sphere is 4πR^2.

6) Owen falls from a tower 9.3*10^3m high. He is falling at a constant speed of 1.2*10^4 km/h. How long does it take him to hit the ground? 3.S.F

7)How much weight crosses the Brooklyn bridge per day if the average car weights 2*10^3 kg aand in 2012 4.38*10^7 cars crossed(In one year). Give your answer as an ordinary number.

8) An Archaeopteryx's tail feather is 9.73*10^7 nanometers long. It increases by 2.43*10^3 nanometres every week. How long is it's feather after 3 days. Give your exact answer in standard form.

9) A goal was taken from 1.35*10^ -2 km from the net at a constant speed of 35m/s. How long did it take?

10)Assume that out galaxy is a cylinder. The diameter is 1.1*10^5 light years and the height is 3.2*10^2 light years. 1 light year = 9.5*10^12 km.

A) Work out the surface area to 3 sig figs in both square light years and square Km.

B) Work out the volume to 3.s.f in both cubic light years and cubic km.

Re: Help with hard Standard Form questions?

Sorry, but we're not going to do your homework for you. Show us your attempt at solving these and we'll help guide where you get stuck. Yuo posted this under a University Math Forum so I'm pretty sure you will get these if you work on them for a few minutes. However, I must say I'm a bit intrigued by question #2 - must be a trick question.

Re: Help with hard Standard Form questions?

I don't even know what standard form is though, I was ill for the entire topic. I would try but I can't. I'm not allowed Facebook so I can't ask my friends. Also I've gone on places like MyMaths and looked at it but it doesn't make sense. I am going to ask a tutor who comes round every Sunday afternoon to help me. The trouble is I need it in for tomorrow (UK time) and it's 8 O'clock. I'm sorry if you think I'm being ungrateful or like I just expect you to be nice to me, I would act the same way you did. Don't worry if you feel you shouldn't help because of my actions then do not. I deserve it.

Re: Help with hard Standard Form questions?

The term "standard form" refers to numbers expressed in the usual way, like you've done since 1st grade - for example in standard form we say the number of days in a year is 365, the number of millimeters in a meter is 1000, and 100 divided by 8 is 12.5.. This is as opposed to scientific notation which expresses numbers in powers of ten: there are 3.65x10^3 days in a year and 1 x 10^3 millimieters in a meter, and 1 x 10^2 divided by 8 is 1.25 x 10 ^1. But the first thing is: do you know how to do the math required in these problems? For example the first question gives you a speed and a distance to be traveled, and to find the time required you simply divide the distance by the speed. What do you get for an answer?

Re: Help with hard Standard Form questions?

You said there are 3.65x10^3 days in a year from what I understand would that not mean 3650 days? 3.65->36.5->365->3650?

Re: Help with hard Standard Form questions?

Ok, I researched a bit and I understand it a bit better. For number one....

1.35*10^3= 1350 m/s

5.5*10^5=55000 metres

So 55000/1350 = 40.740740740740740740740740740741 Seconds? And then 0.679 Minutes

Re: Help with hard Standard Form questions?

Quote:

Originally Posted by

**serilex** You said there are 3.65x10^3 days in a year from what I understand would that not mean 3650 days? 3.65->36.5->365->3650?

Achh! Yep, you got me. The good news is it shows you understand scientific notation!

Re: Help with hard Standard Form questions?

Did you look much at these problems? Your #2 says

Quote:

2) In Mexico they produce around 2 103 360 000 kg of Taco's every year. How many banana's do they produce in 5 Years? (In standard Form, obviously.)

What do bananas have to do with tacos?

Re: Help with hard Standard Form questions?

And about the first question? Did I get it right?

Re: Help with hard Standard Form questions?

Quote:

Originally Posted by

**serilex** Ok, I researched a bit and I understand it a bit better. For number one....

1.35*10^3= 1350 m/s

5.5*10^5=55000 metres

You need one more 0 in there: 5.5x 10^5 = 550000.

Quote:

Originally Posted by

**serilex** So 55000/1350 = 40.740740740740740740740740740741 Seconds?

Notwithstanding that this is off by a factor of ten due to the previous error -- you should show results only to the same level of precision as the data you were given. In this case you are given a data to three significant digits, so including more than three significant digits in your answer is not correct. Thus 55000/1350 = 40.7.

Re: Help with hard Standard Form questions?

Quote:

Originally Posted by

**HallsofIvy** Did you look much at these problems? Your #2 says

What do bananas have to do with tacos?

Like I suggested - must be a trick question. You know if they asked about banana production in Canada over a period of five years then I would understand. But bananas do actually grow in Mexico, so the answer is not at all obvious.

Re: Help with hard Standard Form questions?

I see what you mean with the second one, also. It's a weight, and they're asking how many. I'm guessing it's just 2103360000*5 converted to standform which is 1.05168x10^10.

Re: Help with hard Standard Form questions?

I was thinking of Taco's damnit.

Re: Help with hard Standard Form questions?

Well I have to go to be. Parents shouting. Got to end of Q3. 1=40.7? 2=1.05168x10^10kg 3=3.78421136x10^14

I expect I will have to do it for friday when my teachers tell me off tommorow so I might be back. Thankyou for forgiving me for being rude and helping me very much

Re: Help with hard Standard Form questions?

I never meant to imply that you were being rude - not at all. Now that you're showing us your work I am quite happy to help you along.

As for your first three answers: 1 is off by a factor of ten (as I noted previously), and 2 and 3 are good except that you are using scientific notation instead of standard form. So I think the answer to 2 should be 10516800000 Kg.