Final answer:
The rate at which the man's shadow is increasing in length is approximately -0.572 m/s.
Step-by-step explanation:
To find the rate at which the shadow is increasing in length, we can use similar triangles. Let's denote the length of the shadow as S and the distance between the man and the lamppost as D.
Since the height of the man is 1.1 meters and the length of the lamppost is 5 meters, we have:
S / D = 1.1 / 5
Solving for S, we get:
S = (1.1 / 5) * D
Now, we can find the rate at which the shadow is increasing by taking the derivative with respect to time:
dS/dt = (1.1 / 5) * dD/dt
Since the man is walking away from the lamppost at a speed of 2.6 m/s, we have:
dD/dt = -2.6 m/s
Substituting the values, we get:
dS/dt = (1.1 / 5) * (-2.6) m/s
Simplifying, we find that the rate at which the shadow is increasing is approximately -0.572 m/s.