Please correct my work.

Both Part A are correct but I got incorrect for both Part B

(04.03 HC) Sand is being poured into an open right circular cone container, as shown in the gure. The height of the container is 8 cm, 2 and the diameter of the opening is 8 cm. Sand is being poured in so that its depth h is changing at a constant rate of E cm/min. ' \\ T\" 8 cm h v = lxrzh. (Note: The volume of a cone of height h and radius r is given by 3 ) Part A: Find the volume V of sand in the container when h = 4 cm. Indicate units of measure. (10 points) Part B: Find the rate of change of the volume of sand in the container, with respect to time, when h = 4 cm. Indicate units of measure. (20 points) Part A: V = - Trz h when h = 4cm, = so, r = 2 cm When h = 4 cm, v = 1 - Tir h = T . 23 . 4 16 = - TT cm3 3 Part B: 4 dt 10 cm/min when h = 4 cm dv 2 71 . h = d- dt dt dh TT . dt COCO / CO | H 4 - TT 10 = cm 15 min(04.01 HC) The equation of motion for a particle moving along the yaxis is given as y(t) = 21'2 8t + 3 for t a 0. Part A: Find the velocity and acceleration functions. (10 points) Part B: Describe where the particle changes direction and the intervals where the particle speeds up or slows down. (20 points) The equation of motion y = 2t2 - 8t + 3 Part A: Now find the first and second derivative dy = 4t - 8 (velocity) dt day = 4 (acceleration) at2 Part B: The particle speeds up when acceleration is positive and the particle slows down when acceleration is negative. Speeding up = (0, 0o)