Question

Given that velocity of B is (3i+4j) m/s
Given instead that B has speed 8 m/s.
Why is the new velocity 1.6(3i+4j)??

Answer 1

speed is the magnitude of velocity

whats the magnitude of 3i+4j ?

Answer 2

5

Answer 3

then you'll just have to check,
new speed is how many times the old speed??

the same will be true for velocity,
new velocity will be that many times the old velocity :)

Answer 4

8 is how many times 5 ? :)

Answer 5

speed is the magnitude of velocity, so you can find the magnitude of your direction vector by doing the square root of (3squared + 4squared). this'll give 5, and divide 8/5 to get the number of times you need to multiply the direction vector to get the right speed.

Sooo the velocity will be 1.6(3i + 4j) :D

Answer 6

Thank you so much!

Answer 7

Np ::)