can you please check my work. sorry to repost but I was skipped over earlier and just want to know if I did this correctly?
A scientist uses a submarine to study ocean life.
She begins at sea level, which is at an elevation of 0 ft.
she travels straight down at a speed of 3.5ft per second.
she then travels directly up 30seconds at a speed of 2.2ft per second.
1) after 120 seconds, what is the scientist's elevation?
MY WORK:
I multiplied 90x3.5=315 ft, then I mult. 30x2.2=66
then I subtracted 315-66=249ft down.
249 ft
2)If the submarine travels at a maximum speed of 5 feet per second, how long would it take to return to sea level? round to the nearest second.
I took the answer from the first part 249 ft and divided it by 5 = 49.8 so I made it 50 seconds.
Are these correct? Thanks for looking over my work
looks good
thank you so much.
Let's check your work step by step to see if your answers are correct.
1) After 120 seconds, what is the scientist's elevation?
You correctly calculated the distance travelled during the descent: 90 seconds multiplied by the speed of 3.5 ft/s equals 315 ft. However, your calculation for the ascent is incorrect. Instead of multiplying 30 seconds by 2.2 ft/s, you should multiply it by -2.2 ft/s since the scientist is going up, which is opposite to the positive direction. So the correct calculation would be -30 seconds multiplied by -2.2 ft/s, which equals 66 ft.
To find the scientist's final elevation, you need to add the distance travelled during the descent and subtract the distance travelled during the ascent. Therefore, 315 ft (descent) minus 66 ft (ascent) equals a final elevation of 249 ft.
So your answer for the scientist's elevation after 120 seconds is indeed correct: 249 ft.
2) If the submarine travels at a maximum speed of 5 feet per second, how long would it take to return to sea level? Round to the nearest second.
To determine the time it takes to return to sea level, you need to divide the distance of 249 ft by the speed of 5 ft/s. However, you mistakenly divided it by 5 instead.
The correct calculation would be: 249 ft divided by 5 ft/s equals approximately 49.8 seconds. Since you were asked to round to the nearest second, the answer would be 50 seconds.
So your answer for the time it takes to return to sea level is incorrect. The correct answer is approximately 50 seconds, not 49.8 seconds.
In conclusion, your first answer for the scientist's elevation after 120 seconds (249 ft) is correct, but your second answer for the time it takes to return to sea level (49.8 seconds) is incorrect. The correct answer is approximately 50 seconds.