If the outer planets in the solar system have more mass, shouldn't they therefore have more gravitational pull and be closer to the sun? I'm confused about this and it concerns my work, but I tried to google it and no explanation came up.

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.