going across the puddle,
s = 20t - 1/2 at^2 = 25
v = 20 - at = 5
solve for a and t.
s = 20t - 1/2 at^2 = 25
v = 20 - at = 5
solve for a and t.
acceleration (a) = (final velocity (v_f) - initial velocity (v_i)) / time (t)
In this case, the initial velocity (v_i) is 20 m/s, the final velocity (v_f) is 5 m/s, and we need to find the time taken to cross the puddle.
So, let's start by calculating the acceleration:
a = (v_f - v_i) / t
We know that v_i = 20 m/s, v_f = 5 m/s, and t is the time taken to cross the puddle. Now, we need to find the time.
With constant acceleration, we can use the formula of motion:
v_f^2 = v_i^2 + 2aΔx
Here, Δx represents the displacement or distance traveled, which is given as 25 m (width of the puddle).
Plugging in the values:
5^2 = 20^2 + 2a * 25
25 = 400 + 50a
25 - 400 = 50a
-375 = 50a
Now we can solve for the acceleration (a):
a = -375 / 50
a = -7.5 m/s^2
The mud buggy's acceleration while driving through the puddle is -7.5 m/s^2 (negative because it's slowing down).
To find the time taken to cross the puddle, we can use the equation of motion:
Δx = v_i * t + (1/2) * a * t^2
Since we know v_i = 20 m/s, a = -7.5 m/s^2, and Δx = 25 m, we can rearrange the equation:
25 = 20 * t + (1/2) * (-7.5) * t^2
25 = 20t - 3.75t^2
Rearranging again:
3.75t^2 - 20t + 25 = 0
Now, we can solve this quadratic equation to find the time (t).