When a car accelerates from a standing start, the crash test dummy appears to be pressed backward into the seat cushion. which of the following best explains why this happens?

a. the crash test dummy gets lighter as the car accelerates.
b. the car is moving forward faster than the crash test dummy.
c. there is no reaction to the force of the car taking off.
d. gravity is pulling the crash test dummy in the direction the car is moving.

Option: D. Gravity is pulling the crash test dummy in the direction the car is moving.

Explanation:

When a car accelerates from a standing start, the crash test dummy appears to be pressed backward into the seat cushion because the gravity is pulling the crash test dummy in the direction the car is moving.  

Basically when the car is starting, the person inside is in static position and the car is going to move. So it is putting a force on the person to move on the same speed. But as the person is sitting static hence gravity is pulling him behind from moving. Hence, The dummy appears to be pressed backward.

none, its a machine