a car moving with an initial velocity of 60 m/s south has a constant acceleration of 10 m/s^2 north. After 12 seconds its velocity will be:
A) 60 m/s south B)60 m/s north C) 40 m/s north D) 40 m/s south
Use the following formula and solve for Vf
Vf=Vi+at
Where
Vf=?
Vi=60m/s
a=-10m/s^2
t=12s
**Since the acceleration is in the opposite direction of the velocity, acceleration is negative.
Vf=60m/s+[(-10m/s^2)(12s)]
Vf=-60m/s
Velocity is in the opposite direction, then velocity initial, so -60m/s is 60m/s north
B is the best answer choice.
To find the velocity of the car after 12 seconds, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time taken.
Given:
Initial velocity (u) = 60 m/s south
Acceleration (a) = 10 m/s^2 north
Time (t) = 12 seconds
We need to determine the final velocity (v).
First, let's determine the direction of the final velocity:
The initial velocity is south (negative direction), and the acceleration is north (positive direction). The velocity will change its direction from south to north over time.
Now, let's find the magnitude of the final velocity:
Using the equation v = u + at, we can substitute the given values:
v = 60 m/s south + (10 m/s^2 north)(12 s)
To add the velocities, we need to consider their directions. Since one is in the negative direction (south) and the other in the positive direction (north), we subtract the magnitudes:
v = |60| - |10|(12)
Calculating this:
v = 60 m/s - 120 m/s
v = -60 m/s
Since the magnitude of the final velocity is 60 m/s and the direction is south (negative direction), the answer is D) 40 m/s south.