we are asked to determine the kinetic energy of an object that has a mass of 4.96g. To do that we will use the following formula:

Where:

First, we will convert the mass into kilograms using the following conversion factor:
![1\operatorname{kg}=1000g]()
Now we multiply the mass by the conversion factor in decimal form:
![4.96g*\frac{1\operatorname{kg}}{1000g}=0.00496\operatorname{kg}]()
Now, we convert the velocity into meters per second by converting kilometers into meters. To do that we will use the following conversion factor:
![1\operatorname{km}=1000m]()
Now, we multiply the velocity by the conversion factor:
![49.1\frac{\operatorname{km}}{s}*\frac{1000m}{1\operatorname{km}}=49100(m)/(s)]()
Now, we substitute the values in the formula for the kinetic energy:

Solving the operations:

And thus we have determined the kinetic energy of the meteorite.