Answer Happy

3. [-/0.14 Points] If a ball is thrown vertically upward with an initial velocity of 96 ft/s, then its height after t seconds is s = 96t - 16t2. (Consider up to be the positive direction.) (a) What is the maximum height (in ft) reached by the ball? ft (b) What is the velocity (in ft/s) of the ball when it is 128 ft above the ground on its way up? ft/s What is the velocity (in ft/s) of the ball when it is 128 ft above the ground on its way down? ft/s Need Help? 4. [-/0.14 Points] DETAILS SCALCET9 3.7.010.MI. (b) after 4 s (c) after 7 s Need Help? Read It DETAILS A stone is dropped into a lake, creating a circular ripple that travels outward at a speed of 60 cm/s. Find the rate (in cm²/s) at which the area within the circle is increasing after each of the following. (a) after 1 s cm²/s cm²/s cm²/s Watch It Read It Master It SCALCET9 3.7.016.

10. [-/0.14 Points] DETAILS The mass of the part of a metal rod that lies between its left end and a point x meters to the right is 2x² kg. (a) Find the linear density (in kg/m) when x is 3 m. kg/m SCALCET9 3.7.019. (b) Find the linear density (in kg/m) when x is 4 m. kg/m (c) Find the linear density (in kg/m) when x is 9 m. kg/m Where is the density the highest? O At the right end of the rod. At the left end of the rod. In the middle of the rod. Where is the density the lowest? At the right end of the rod. At the left end of the rod. O In the middle of the rod.

11. [-/0.14 Points] The quantity of charge Q in coulombs (C) that has passed through a point in a wire up to time t (measured in seconds) is given by Q(t) = t³- 2t² + 7t + 4. [The unit of current is an ampere 1 A = 1 C/s.] (a) Find the current (in A) when t = 0.1 s. A DETAILS SCALCET9 3.7.021. (b) Find the current (in A) when t = 1 s. At what time (in s) is the current the lowest? t = Need Help? Read It Watch It