Answer:
Oscillation whose amplitude reduce with time are called damped oscillation. This happen because of the friction. In oscillation if its amplitude doesn't change with time then they are called Undamped oscillation
Answer:

Explanation:
we know that
The formula to calculate the acceleration is

we have



substitute


U = 80mph = 35.76m/s
S = 0.8m
M = 3500kg
To find the deceleration, we use equation of motion to calculate that
V² = u² + 2as
But v = 0
0 = u² + 2as
-U² = 2as
a = -u² / 2s
a = -(35.76)² / (2 * 0.8)
a = 1278.78 / 1.6 = 799.24 m/s²
The force exerted on the truck during deceleration is equal to the summation of all the forces acting on the truck.
∑F = m. ⃗a
-F = 3500 * 799.24
F = -2797331.25N
F = -2797.33kN
F = -2.797MN.