**Given Information:**
- Dimensions of the object: 3×4×5 cc
- Initial temperature: 10 degrees
- Final temperature: 20 degrees
- % change in length: 2%

**Calculating Change in Length:**
The % change in length can be calculated using the formula:

% change in length = (change in length / initial length) × 100

Let's assume the initial length is L. So the change in length can be calculated as:

(change in length) = (2/100) × L

**Calculating New Length:**
The new length after heating from 10 degrees to 20 degrees can be calculated using the formula:

new length = initial length + change in length

The initial length is L, and the change in length is (2/100) × L. Therefore,

new length = L + (2/100) × L

**Calculating Change in Volume:**
The change in volume can be calculated using the formula:

change in volume = (change in length) × (initial width) × (initial height)

The initial width is W and the initial height is H. Therefore,

change in volume = (2/100) × L × W × H

**Calculating New Volume:**
The new volume after heating from 10 degrees to 20 degrees can be calculated using the formula:

new volume = initial volume + change in volume

The initial volume is L × W × H, and the change in volume is (2/100) × L × W × H. Therefore,

new volume = L × W × H + (2/100) × L × W × H

**Calculating % Change in Volume:**
The % change in volume can be calculated using the formula:

% change in volume = (change in volume / initial volume) × 100

The initial volume is L × W × H and the change in volume is (2/100) × L × W × H. Therefore,

% change in volume = [(2/100) × L × W × H] / (L × W × H) × 100

Simplifying the equation,

% change in volume = 2%

Therefore, the % change in volume when the object is heated from 20 degrees to 60 degrees is 2%.