{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

HW #1-2-solutions

# HW #1-2-solutions - pasha(sep635 HW#1-2 Antoniewicz(56445...

This preview shows pages 1–3. Sign up to view the full content.

pasha (sep635) – HW #1-2 – Antoniewicz – (56445) 1 This print-out should have 30 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 7) 3.0 points A spacecraft is observed to be at loca- tion 200 m , 300 m , - 400 m relative to an origin located on a nearby asteroid, and 5 s later it is observed to be at location 425 m , 25 m , - 650 m . Find the average ve- locity of the spacecraft, ¯ v = v x , v y , v z . What is v x in m/s? Correct answer: 45 m / s. Explanation: The average velocity of the spacecraft is calculated by finding the change of position over a change in time: ¯ v = r f - r i Δ t . Because r is a vector, the average velocity will also be a vector and each component must be calculated separately. For ¯ v x the value becomes: ¯ v x = v 2 x - v 1 x Δ t = (425 m) - (200 m) (5 s) = 45 m / s 002 (part 2 of 7) 3.0 points What is v y in m/s? Correct answer: - 55 m / s. Explanation: The average velocity of the spacecraft is calculated by finding the change of position over a change in time: ¯ v = r f - r i Δ t . Because r is a vector, the average velocity will also be a vector and each component must be calculated separately. For ¯ v y the value becomes: ¯ v y = v 2 y - v 1 y Δ t = (25 m) - (300 m) (5 s) = - 55 m / s 003 (part 3 of 7) 2.0 points What is v z in m/s? Correct answer: - 50 m / s. Explanation: The average velocity of the spacecraft is calculated by finding the change of position over a change in time: ¯ v = r f - r i Δ t . Because r is a vector, the average velocity will also be a vector and each component must be calculated separately. For ¯ v z the value becomes: ¯ v z = v 2 z - v 1 z Δ t = ( - 650 m) - ( - 400 m) (5 s) = - 50 m / s 004 (part 4 of 7) 4.0 points What is | v | in m/s? Correct answer: 86 . 8907 m / s. Explanation: The magnitude is calculated by: | v | = v 2 x + v 2 y + v 2 z = (45 m / s) 2 + ( - 55 m / s) 2 + ( - 50 m / s) 2 = 86 . 8907 m / s 005 (part 5 of 7) 3.0 points

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
pasha (sep635) – HW #1-2 – Antoniewicz – (56445) 2 Find the unit vector in the direction of the velocity of the spacecraft, ˆ v = ˆ v x , ˆ v y , ˆ v z . What is ˆ v x ? Correct answer: 0 . 517892. Explanation: The unit vector for a vector is given as : ˆ v = ˆ v x , ˆ v y , ˆ v z = v x , v y , v z | v | For example: ˆ v x = v x | v | = 45 m / s 86 . 8907 m / s = 0 . 517892 006 (part 6 of 7) 3.0 points What is ˆ v y ? Correct answer: - 0 . 632979. Explanation: The unit vector for a vector is given as : ˆ v = ˆ v x , ˆ v y , ˆ v z = v x , v y , v z | v | For example: ˆ v y = v y | v | = - 55 m / s 86 . 8907 m / s = - 0 . 632979 007 (part 7 of 7) 2.0 points What is ˆ v z ? Correct answer: - 0 . 575435. Explanation: The unit vector for a vector is given as : ˆ v = ˆ v x , ˆ v y , ˆ v z = v x , v y , v z | v | For example: ˆ v z = v z | v | = - 50 m / s 86 . 8907 m / s = - 0 . 575435 008 (part 1 of 7) 3.0 points Here are the positions at three di ff erent times for a bee in flight (a bee’s top speed is about 7 m/s .
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}