a. To calculate acceleration, we use the formula acceleration = (final velocity - initial velocity) / time. Plugging in the values, we get acceleration = (0 m/s - 15 m/s) / 0.5 s = -30 m/s^2.
b. According to Newton's Second Law of Motion, force = mass x acceleration. Given that the mass of Vehicle 3 is not provided, we cannot calculate the force exerted on the wall.
c. Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. Therefore, the force exerted by the wall on Vehicle 3 will be equal in magnitude but opposite in direction to the force exerted by Vehicle 3 on the wall.
d. To calculate the acceleration of the bus, we use the formula acceleration = force / mass. Given that the force is not known, we cannot calculate the acceleration of the bus.
e. Since Vehicle 3 comes to a stop upon collision with the wall, its velocity will be decreasing after the collision. This is because the force exerted by the wall on Vehicle 3 causes it to decelerate and ultimately come to a stop.