Science Homework. Correct Answers will receieve bonus 10 points!?

Question

I finished my science homework but I wanted to make sure I had the right answers. It's a HUGE part of my grade.

1.) cardboard boxes manufactured for refrigerators measure 1.88 m x 0.92 m x 0.86m. What is the volume of this box in m3 (meter cubed)? In cm 3 (cm cubed)? Express the cm3 in scientific notation.

2.) During a recent Leonids meteor shower, astronomers reported an average of 1.38 x 10 to 4th power. shooting stars/hour over a period of 2.4 hours. how many meteors were seen during the entire 2.4 hour period?

3.) A rest stop along the highway is at mile marker 1453 km. The next rest stop is at marker 1615. How many km apart are these rest stops?

4.) Venus comes closer to Earth than any other planet, approaching as closely as 4.02x10 to seventh power km. Neptuneis one of the most distant planets, being 4.35x 10 to the ninth power km at its closest. What is the differenceof these two numbers?

5.) Three large properties are listed "For Sale" by a realtor. Their areas are 20.34 km squared, 18.0 km spaured, and 25.333 km squared. What is the total area of these three properties?

6.) A small roll of tape is 1.2 x 10 negative two to the power meters wide and 6.35 meters long. What is the tape's total surface area?

7.) Calculate the volume of a swimming pool measureing 20.46 meters x 3.6576 meters x 2.25 meters.

8.) A racecar covered the length of a 12,633.35 meter track in 112.67 seconds. What was its average speed?

9.) Secreatariat won the 1973 Kentucky derby, running the 2011.86 meter track ub 199.4 seconds. What was his average speed?

10.) In the first nonstop trans-Pacific flight in 19312, the plane traveled 7,335,390 meters in 148,380 seconds. What was its speed in m/s? How about in km/hr?

11.) A cross-country skier covered 415,532.6 meters in 24 hours. What was the skier's average speed? Express your answer both in m/s and km/h.

PLEASE AND THANK YOU!

These are significant Figures by the way. its a 9th grade CP class.

Answer 1

8 and 11 speed equals distance over time

Answer 2

1. 1.5 x 10^6 cm^3, 1.5 m^3

2. 3.3 x 10^4 meteors

3. 162 km

4 4.31 x 10^9 km

5. 45.6 km^2

6. 0.076 m^2

7. 168 m^3

8. 112.13 meters/second

9. 10.09 meters/second

10. 49.4365 meters/ second, 49465.5 km/second

11. 0.48 meters/s, 1.7 x 10^7 km/h

Answer 3

1) to find the volume, just multiply the length, width and height of the box:

1.88 m x 0.92 m x 0.86m = 1.487456 m cubed

to calculate this in cm cubed, first think of the connection between m and cm. 1m=100 cm, so 1 m cubed=1 m x 1m x 1m = 100cm x 100 cm x 100 cm=10 to the 6 power cm cubed

so, the volume in cm cubed is

1.487456  x 10 to the 6 power cm cubed=1,487,456 cm cubed

2) here you have to multiply the average shooting stars/hour by the length of the period (it's like the formula for the speed x time = distance). So, here you get:

1.38 x 10 to 4th power x 2.4 = 33,120 shooting stars total

3) Well, this one is simple - just calculate the difference

1615 - 1453 = 162 km

4) Here, for easier calculations, you can take out of brackets the lower power of 10, so you get:

4.35 x 10 to the 9th - 4.02 x 10 to the 7th = 10 to the 7th x (435 - 4.02) =430.98 x 10 to the 7th power km = 4.3098 x 10 to the 9th power km

5) This one is simple, too. Just add the area of the three properties and you get the total :)

20.34 +18.0 + 25.333 = 63.673 km squared

6) to find the surface area of a rectangular piece just multiply the length and the width:

6.35 x 1.2 x 10 to the (-2) power = 7.62 x 10 to the (-2) power m squared.

However, the roll of tape has two sides, so the area is actually twice bigger than our result - one time for the upper side and once for the other side.

Finally, the answer is

2 x 7.62 x 10 to the (-2) power = 15.24 x 10 to the (-2) power m squared

7) as in 1), the volume is calculated by multiplying the length, width and height:

20.46 x 3.6576 x 2.25 = 168.377616 m cubed

8) to calculate the average speed, divide the traveled distance by the time the traveling took:

12,633.35 / 112.67= 112.127 m/s approximately

9) this one is the same as 8:

2011.86 / 199.4 = 10.0896 m/s approximately

10) the first part of the question is just like the above two:

7,335,390 / 148,380 = 49.4365 m/s approximately

to calculate this in km/h we have to see first what happens for 1 m/s

1m/s = 0.001 km / (1/3600) h (because 1m= 0.001 km and 1 s = 1/60 minute = 1/3600 hour)

so, 1 m/s = 3.6 km/h

Thus, 49.4365 m/s = 49.4365 x 3.6 km/h = 177.9714 km/h

11) For m/s, we have to see how many seconds there are in 24 hours. In one hour there are 3600 seconds, so in 24 hours there are

24 h = 24 x 3600 s = 86,400 s

Thus, the speed in m/s is

415,532.6 / 86,400 = 4.094 m/s approximately

to calculate in km/h we could either use that 1 m/s = 3.6 km/h or we could use that 1 m = 0.001 km. Both methods may give different results because we work with approximate values.

I'll use the second method because I used the first one in the previous problem:

415,532.6 m = 0.4155326 km

0.4155326 km/ 24 h = 0.0173 km/h approximately

I hope I helped you :)

Answer 4

Remember, leading zeros don't count when you're counting sig figs (because they can always be done away with by changing to scientific notation).  Zeros to the right of the decimal do, and to the right of the numbers if there's a decimal after the zero(s).  Once you know how many sig figs are in each number given in the problem, find the least number of sig figs in any of those number.  Then give your answer in that number of sig figs -- but always do the calculation using all the digits of all the numbers you are given!

1) 1.5m^3

1.5 x 10^-6 cm^3

2) 3.3 x 10^4 meteors

3) 162.0 km

4) 4.31 x 10^9 km

5) 63.7 km^2

6) 7.6 x 10^-2 m^2, or 0.076 m^2

7) 168 m^3

8) 112.13 m/s

9) 10.09 m/s

10) 49.437 m/s

177.97 km/hr

11) 4.8 m/s

17 km/hr

Good luck!