In 7.50 s, a 7.00 kg block is pulled through a distance of 4.00 m on a frictionless horizontal surface, starting from rest. The block has a constance acceleration and is pulled by means a of horizontal spring that is attached to the block. The spring constant is 415N/m. By how much does the spring stretch?

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.