A 2.5. Gram arrow enters a 100 g apple with a speed of 115 m/s. If the apple was originally at rest, then what speed will it have as the arrow enters it? Remember the formula is P=MxV

The speed of the apple will be 2.81 m/s when the arrow enters it.

Explanation:                

We can find the speed of the apple by conservation of linear momentum:

Where:

is the mass of the apple = 100 g = 0.1 kg

is the mass of the arrow = 2.5 g = 0.0025 kg

and is the initial and final speed of the  apple respectively

and is the initial and final speed of the  arrow respectively

Since the apple was originally at rest ( = 0) and knowing that = when the arrow enters into the apple, we have:

Therefore, the speed of the apple will be 2.81 m/s when the arrow enters it.

I hope it helps you!