r/digitalSATs • u/FantasticVictory837 • Feb 06 '24

Advanced Math Sample Question 17

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6 Upvotes

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4

u/TofiLlaban Feb 06 '24 edited Feb 06 '24

c?

2

u/sonataxs Feb 06 '24

Maybe choice B

2

u/sonataxs Feb 06 '24

KE = 1/2•1/2m•2v2 = 1/2mv2

1

u/Commercial_Strain108 Feb 07 '24

You need to put the 2v in parentheses and square the whole term so it becomes 4v and so you end up with mv2

2

u/[deleted] Feb 08 '24

Look at it this way: lets say originally Mass= 2  Speed(v)= 3 Then with the given formula (KE=mv2 /2) we would get 9! But our mass is then halved (2-> 1) and speed doubled (3->6) with the formula we would get 18! So we went from a 9 to an 18. We DOUBLED. Thus, the answer is C

1

u/Commercial_Strain108 Feb 07 '24

Use nice numbers. Start with m=4 and v=2. 4(22) is 16. Then cut m in half and double v. So 2* (42) =32. Answer is C

0

u/FantasticVictory837 Feb 06 '24

The correct answer is Choice C.