Kevin has a mass of 87 kg and is skating with in-line skates. he sees his 22-kg younger brother up ahead standing on the sidewalk, with his back turned. coming up from behind, he grabs his brother and rolls off at a speed of 2.4 m/s. ignoring friction, find kevin’s speed just before he grabbed his brother.

Explanation:

Using the conservation of the linear momentum P:

so:

where is the mass of kevin, is the velocity of kevin before he grabs her brother, is the velocity of her brother and him after grabs her brother and is the velocity of both after the collition.

So, replacing the values and solving for Vk, we get:

i really dont know but i will try okay.

so i think u would just add all them up and get your answer..