The key to solve this problem is the conservation of momentum. The momentum of an object is defined as the product between the mass and the velocity, and it's usually labelled with the letter
:

The total momentum is the sum of the momentums. The initial situation is the following:

(it's not written explicitly, but I assume that the 5-kg object is still at the beginning).
So, at the beginning, the total momentum is

At the end, we have

(the mass obviously don't change, the new velocity of the 15-kg object is 1, and the velocity of the 5-kg object is unkown)
After the impact, the total momentum is

Since the momentum is preserved, the initial and final momentum must be the same. Set an equation between the initial and final momentum and solve it for
, and you'll have the final velocity of the 5-kg object.
Answer:
Divide by 3
Explanation:
In order to estimate the distance traveled by a lightening flash in kilometers, we follow these simple steps:
- Make a count of the number of seconds in between the period a flash occur and the thunder accompanied by the lightening flash is heard.
- Dive the total number of seconds by 3 to get the distance traveled by the flash. This is because in order to cover 1 km, it roughly takes 3 seconds.
Can you show the diagram please
John used smothering as the method to control the harmful invasive plants in his orchard. Smothering is an example of a manual method of control and it works best in a small population of invasive species. Smothering involves covering the invasive species with a barrier that is highly impenetrable for one growing season in order to prevent these species from thriving in the environment.