To find the density of Lenny's matchbox car, we can use the formula for density:
\[ D = \frac{m}{v} \]
where:
- \( m \) is the mass of the object (in grams),
- \( v \) is the volume of the object (in milliliters).
First, we have the mass of the matchbox car, which is given as 10 grams.
Next, we need to determine the volume of the matchbox car. The volume can be calculated from the change in water level in the graduated cylinder:
Initial water level = 41 ml
Final water level = 46 ml
Volume of the matchbox car \( v \) is:
\[ v = \text{Final water level} - \text{Initial water level} \] \[ v = 46, ml - 41, ml = 5, ml \]
Now we can plug the values into the density formula:
\[ D = \frac{10, g}{5, ml} = 2, g/ml \]
So the density of the matchbox car is 2 g/ml.
The correct answer is B 2 g/ml.