A2kg railroad car is rolling 6.00m/s when 7000kg olaf id gravel is suddenly dropped in. what’s the cars speed after gravel is loaded ?

The cars speed after the gravel is loaded, V = 4.44 m/s

Explanation:

Given data,

The mass of the railroad car, m = 20000 kg

The velocity of the railroad car, v = 6 m/s

The mass of the dropped gravel, m =7000 kg

The momentum of the railroad car,

                                 P = mv

                                    = 20000 x 6

                                    = 120000 kg m/s

According to the law of conservation of momentum,

                                 P = V (M + m)

                                 V = P/ (M + m)

                                    = 120000 / (20000 + 7000)

                                    = 4.44 m/s

Hence, the cars speed after the gravel is loaded, V = 4.44 m/s

v=ir = 3x15 =45 v

because growing process had stoped after 4-5 year