Question

Saki is ice-skating to the left with a velocity of 5 m/s. A steady breeze starts blowing, causing Saki to accelerate leftward at a constant rate of 1.5 m/s². After 6 seconds, what is Saki's velocity? Answer using a coordinate system where rightward is positive.

Option 1:-4.5 m/s
Option 2: 4.5 m/s
Option 3: -6.5 m/s
Option 4: 6.5 m/s

Answer 1

Saki's final velocity after accelerating to the left for 6 seconds is -14 m/s, which means she is moving to the left at 14 m/s.

Step-by-step explanation:

Saki is ice-skating to the left with an initial velocity of -5 m/s (since leftward is considered negative in our coordinate system where rightward is positive). She experiences a constant acceleration to the left of -1.5 m/s². To find Saki's velocity after 6 seconds, we can use the kinematic equation:

v = v₀ + at

Where v is the final velocity, v₀ is the initial velocity, a is the acceleration, and t is the time.

Substituting the given values:

v = (-5 m/s) + (-1.5 m/s²)(6 s) = -5 m/s - 9 m/s = -14 m/s

Therefore, Saki's final velocity is -14 m/s, which indicates that she is moving leftward at 14 meters per second after 6 seconds.