please help with these

15. Use a left and right Riemann Sum to approximate the area under this curve on the interval [0, 4] . Which gives an underestimate? Overestimate? O Left is an overestimate, right is an underestimate. Q It depends on the size of the rectangles used. 0 Left is an underestimate, right is an overestimate. 0 Both are underestimates. 0 Both are overestimates. 16. The position in feet of a particle is given by the equation x (t) = t3 4132 + 6. At what time t > U (in seconds) will the velocity of the particle reach 35 feet per second? 17. A spherical balloon is increasing in volume at a rate of 30 (31113 /min. At What rate is the radius increasing when the balloon has a volume of 8011' cm3'? Round to the nearest 3rd decimal place. (Remember that the volume of a sphere is given by V = gTs). O 1.928 cm/min O 0.467 cm/min O 0.122 cm/min O 0.156 cm/min O 1.545 cm/min