An Australian emu is running due north in a straight line at a speed of 13.0 m/s and slows down to a speed of 10.9 m/s in 3.70 s. (a) What is the magnitude and direction of the bird’s acceleration? (b) Assuming that the acceleration remains the same, what is the bird’s velocity after an additional 2.50 s has elapsed?

change in velocity / change in time = acceleration = (10.9 -13)/3.70

= -.568 m/s^2
North is positive , so the negative result means acceleration is south.
v = Vi + a t
= 10.9 - .568(2.50)
= 9.48 m/s north

A jogger accelerates from rest to 3.0 m/s in 2.0s. A car accelerates from 38.0 to 41.0 m/s also in 2.0s. (a) Find the acceleration (magnitude only) of the jogger. (b) Determine the acceleration (magnitude only) of the car. (c) Does the car travel faster than the jogger during the 2.0s? if so, how much further?

(a) Well, it seems that we have a speedy emu on our hands! To find the acceleration, we can use the formula a = (vf - vi) / t, where vf is the final velocity, vi is the initial velocity, and t is the time taken.

Using these values, we find:
a = (10.9 m/s - 13.0 m/s) / 3.70 s

Calculating this, we get:
a ≈ -0.56 m/s²

The negative sign indicates that the emu is accelerating in the opposite direction to its initial velocity, so the magnitude of the acceleration is 0.56 m/s², and its direction is south.

(b) Assuming that the acceleration remains constant, we can use the formula v = vi + at to find the velocity after an additional 2.50 s has passed.

Using the values we have:
vi = 10.9 m/s (final velocity from part a)
a = -0.56 m/s² (acceleration from part a)
t = 2.50 s

Plugging these values in, we get:
v = 10.9 m/s + (-0.56 m/s²)(2.50 s)

Calculating this, we find:
v ≈ 10.9 m/s + (-1.40 m/s)

And thus, the emu's velocity after an additional 2.50 s would be approximately 9.50 m/s. Keep running, speedy emu!

(a) To find the magnitude of the bird's acceleration, we can use the formula:

acceleration = (final velocity - initial velocity) / time

Given:
Initial velocity (u) = 13.0 m/s
Final velocity (v) = 10.9 m/s
Time (t) = 3.70 s

Using the formula, we can calculate the magnitude of acceleration:

acceleration = (10.9 m/s - 13.0 m/s) / 3.70 s
acceleration = (-2.1 m/s) / 3.70 s
acceleration = -0.57 m/s²

The negative sign indicates that the acceleration is in the opposite direction of the velocity. Therefore, the magnitude of the bird's acceleration is 0.57 m/s², and since the bird is slowing down, the direction of the acceleration is south.

(b) Assuming that the acceleration remains the same, we can use the formula of motion to find the bird's velocity after an additional 2.50 seconds have elapsed:

final velocity = initial velocity + (acceleration * time)

Given:
Initial velocity (u) = 10.9 m/s
Acceleration (a) = -0.57 m/s²
Time (t) = 2.50 s

Using the formula, we can calculate the bird’s velocity:

final velocity = 10.9 m/s + (-0.57 m/s² * 2.50 s)
final velocity = 10.9 m/s + (-1.43 m/s)
final velocity = 9.47 m/s

Therefore, the bird's velocity after an additional 2.50 s has elapsed is 9.47 m/s, still heading north.

To find the answers to these questions, we can use the equations of motion. Let's break it down step by step:

(a) To find the magnitude of the bird's acceleration, we can use the following equation:

acceleration (a) = (final velocity - initial velocity) / time

Given:
initial velocity (u) = 13.0 m/s
final velocity (v) = 10.9 m/s
time (t) = 3.70 s

Substituting the values into the equation, we get:

acceleration (a) = (10.9 m/s - 13.0 m/s) / 3.70 s

Calculating this, we find:

acceleration (a) = -2.162 m/s²

The negative sign indicates that the acceleration is opposite to the direction of motion (north). Therefore, the magnitude of the bird's acceleration is 2.162 m/s², and its direction is south.

(b) To find the bird's velocity after an additional 2.50 s has elapsed, we can use the following equation:

final velocity (v) = initial velocity (u) + acceleration (a) * time (t)

Given:
initial velocity (u) = 10.9 m/s (note that this is the final velocity from part (a))
acceleration (a) = -2.162 m/s² (note that this is the negative acceleration from part (a))
time (t) = 2.50 s

Substituting the values into the equation, we get:

final velocity (v) = 10.9 m/s + (-2.162 m/s²) * 2.50 s

Calculating this, we find:

final velocity (v) ≈ 10.9 m/s + (-5.405 m/s)

Simplifying further, we get:

final velocity (v) ≈ 5.495 m/s

So, assuming that the acceleration remains the same, the bird's velocity after an additional 2.50 s has elapsed is approximately 5.495 m/s, in the south direction.