An object moves freely at 90° to the direction of a gravitational field - AQA - A-Level Physics - Question 12 - 2019 - Paper 2

The acceleration of an object in a gravitational field is determined by the force exerted by the field on the object. Even when the object moves at 90° to the gravitational field, it is still subject to gravitational acceleration. Therefore, the acceleration is not zero, nor is it in the opposite direction of the gravitational field.

Since the object moves freely at 90° to the gravitational field, the correct understanding is that the direction of acceleration relates to the gravitational influence. Hence, the answer is:

D. at 90° to the direction of the gravitational field.