Which example does NOT show acceleration of an object? A. A car turning at 20 km/h
B. A person walking at a constant speed of 5 km/h
C. A car speeding up on the freeway
D. A mosquito crashing into a windshield

D. A mosquito crashing into a windshield

Explanation:

What does Newton's second law state?

For an object with a constant mass m, the second law states that the force F is the product of an object's mass and its acceleration a: F = m * a. For an externally applied force, the change in velocity depends on the mass of the object.

What does Newton's third law state?

The Third Law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects.

A mosquito crashing into a windshield is an example of the third law which is about reaction-reaction forces not of the second law which is about acceleration