21 kg brick v=6.1 m/s sticks to a 2.9 kg cart v=.26 m/s

v = 6.05 m/s

Explanation:

The mass of the brick, M = 21 kg

The velocity of the brick, U = 6.1 m/s

The mass of the cart, m = 2.9 kg

The velocity of the cart, u = 0.26 m/s

The combined mass of the brick and the cart, v = ?

According to the law of conservation of linear momentum,

         Combined final momentum = sum of the initial momentum

                         (M + m)v = MU + mu

                                      v = MU + mu / M + m

                                         = 21 x 6.1 + 2.1 x 0.26 / (21 + 0.26)

                                         = 6.05 m/s

Hence, the combined velocity of the cart and the brick is, v = 6.05 m/s

half of a circle

explanation:

the arrow and the top of the circle is matching together. it is not a polygon because a polygon would always be the same shape. therefore, an half of a circle is called semicircle so you would find the radius of it.