To determine which object will have the least acceleration when the same force is applied, we can use Newton's second law of motion, which states that acceleration (a) is equal to the force (F) divided by the mass (m) of the object:
\[ a = \frac{F}{m} \]
Since the same force is applied to each object, the acceleration will be inversely proportional to the mass of the object. This means that the object with the greatest mass will have the least acceleration.
From the table, the masses are:
- Textbook: 1.65 kg
- Hardcover novel: 0.88 kg
- Paperback novel: 0.51 kg
- Spiral notebook: 0.54 kg
The textbook has the greatest mass (1.65 kg), so it will have the least acceleration.
Therefore, the answer is: textbook.