Send wave from your location to the object and wait until echo is back.
Measure the time taken.
If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return
Answer:

Explanation:
Acceleration is given by

where
is the change in velocity
is the time interval in which the change in velocity occurs
To find the acceleration at 1 second, we can take the data at t = 1 s and t = 2. We find:


So, the acceleration is

Find the horizontal components vcos30 ...one goes right and one goes left so they cancel each other.
Find vertical components vsin30.....there are two of them.... so 2vcos30....hey presto... resultant velocity = 2vCos30
The gunstock it’s also called stock or shoulder stock