Solve the all parts of given problem:
Problem: A dynamite blast at a quarry launches a rock straight upward, and 1.7 s later it is rising at a rate of 14 m/s. Assuming air resistance has no effect on the rock,
Part A: Calculate its speed at launch?
Part B: Calculate its speed at 4.3 s after launch?
Please show your all work and steps I am really confused.