Final answer:
The width of the base of the rectangular prism is calculated by dividing the given volume (70 cm³) by the product of the given length (7 cm) and height (2 cm), resulting in a width of 5 cm.
Step-by-step explanation:
To find the width of the base of a rectangular prism when the volume, height, and length are known, we use the formula for the volume of a rectangular prism, which is V = l × w × h, where V is the volume, l is the length, w is the width, and h is the height. In this case, the volume (V) is given as 70 cm³, the length (l) is 7 cm, and the height (h) is 2 cm.
We can rearrange the formula to solve for the width (w) as follows: w = V / (l × h). We then substitute the given values into the formula: w = 70 cm³ / (7 cm × 2 cm), which simplifies to w = 70 cm³ / 14 cm², and finally, w = 5 cm.
Thus, the width of the base is 5 cm, which corresponds to option (a).