A person ran with a speed of 6 m/s onto the skateboard .What is the speed with which he ride on the skate board

First, remember the conservation of energy.

We can define the kinetic energy as:

K = (1/2)*m*v^2

where m is the mass, and v is the velocity.

The velocity of the person is 6m/s, and the mass is unknown.

Now, when the person rides the skateboard, this kinetic energy must remain constant, if M is the mass of the skateboard, the speed after the person rides ir will be:

K' = (1/2)*(m + M)*v'^2

Where v' is the new velocity.

In this case, we can suppose that the skateboard has really small mass compared with the person.

M < < m

then:

(m + M) ≈ m

then:

K' = (1/2)*m*v'^2 = K = (1/2)*m*v^2

from that equation, we can conclude that:

v' = v

Then if the velocity before riding the skateboard was 6m/s, then after would be also 6m/s.

does anyone know or what?

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.