A student walks east 100 meters in 2 minutes. She then walks north 200 meters in 4 minutes. Which statement is true?

Question

options:

Her velocity changes because her speed varies.
Her velocity changes because her speed varies.

Her velocity is constant because her direction is constant.
Her velocity is constant because her direction is constant.

Her velocity is constant because her speed is constant.
Her velocity is constant because her speed is constant.

Her velocity changes because her direction changes.
Her velocity changes because her direction changes.

Answer 1

The correct statement is:

Her velocity changes because her direction changes.

Velocity is a vector quantity, meaning it has both magnitude (speed) and direction. The student starts walking east and then changes direction to walk north, which means her velocity is changing even if her speed may remain constant. Therefore, the change in direction results in a change in velocity.

Answer 2

Hector went to the music store by heading due south at 3 m/s, then turning West and continuing at the same speed for another three blocks. Which of the following is true about Hector's velocity?

options:

Hector's velocity did not change because his direction did not change.
Hector's velocity did not change because his direction did not change.

Hector's velocity did not change because his speed did not change.
Hector's velocity did not change because his speed did not change.

Hector's velocity changed because his speed changed.
Hector's velocity changed because his speed changed.

Hector's velocity changed because his direction changed.

Answer 3

The correct statement is:

Hector's velocity changed because his direction changed.

Even though Hector maintains the same speed of 3 m/s, he changes direction when he turns from heading south to heading west. Since velocity is a vector quantity that depends on both speed and direction, changing direction means that his velocity changes.