Question

PLEASE HELP ME WITH THIS IF UR GOOD AT PHYSICS!!! 100 POINTS!!!!

Q 1 . How many significant figures are in the following measurement? 0.0009(1 point)
1


5

4


3

Q 2. Three unique samples are weighed on different scales at separate laboratories across the country. The first has a weight of 31.2 lbs, the second sample weighs 38.02 lbs, while the third measures 45 lbs. How much is the total combined weight of all of these samples?(1 point)


114.22 lbs

110 lbs

114 lbs

114.2 lbs

Q 3. A track coach measures the 100-meter time of a track athlete. The runner completes the distance in 11.5 seconds. If the stopwatch has an uncertainty of 1.7%, what is the amount of uncertainty in the time?(1 point)
(1 point)

11.5 s ± 0.19 s
11.5 s plus or minus 0.19 s

11.5 s ± 0.20 s
11.5 s plus or minus 0.20 s

11.5 s ± 0.1955 s
11.5 s plus or minus 0.1955 s

11.5 s ± 0.196 s


Q 4. The speed of a bullet train is measured to be 312.0 mph ± 3.9 mph. What is the percent uncertainty in this measurement?(1 point)


1.3%

1.2%

1.25%

0.0125%

Answer 1

#1

• 0.0009

3zeros hence significant figures will be 4

#2

`\\ \sf\longmapsto 31.2+38.02+45`

`\\ \sf\longmapsto 114.22lbs`

#3

`\\ \sf\longmapsto 11.5s\pm 0.19s`

• Round it up

`\\ \sf\longmapsto 11.5s\pm 0.20s`

#4

0.0125%

Answer 2

I do apologize but I can't figure out Q 2 , 3 but

Q 1 is 1

Q4 is 0.0125%

so sorry