Got a question ~ can someone help me out ? I want Explanation ~ [ cuz there's something I'm not clear about in this question ]

Thanks for Answering ~

Aparticle initially moving east with a speed of 20.0 m/s, experiences an acceleration of 3.95 m/s, north for a time of 8.00 s. what was the speed of the particle after this acceleration, in units of m/s? give the answer as a positive number.

How is coal extracted from mountaintop removal mines? a. dynamite is used to create underground tunnels where miners go to extract the coal. b. dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal. c. coal in mountaintops is extracted by digging strips in the landscape to reach the coal. d. placer deposits in mountain river bottoms are removed by

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?