WebAssign Lesson 7-3 Applications (Homework)

Transcription

1 WebAssign Lesson 7- Applications (Homework) Current Score : / 2 Due : Monday, March :00 AM MDT Shari Dorsey Sp 4 Math 70, section 00, Spring 204 Instructor: Shari Dorsey. /2 points Suppose that x 2 + y 2 = 00. In this problem: y measures the height of an object in feet. x measures the position of a second object in feet. t is time in seconds. =.5ft/s. Find when x = 8.66 feet and y = 5 feet. 2. /2 points Suppose that x 2 = y. In this problem: y is measured in feet and is a function of time, t. x is measured in feet and is a function of time, t t is measured in seconds. Find when x = 8 feet, y = 4 feet, and = ft/s.. /2 points Suppose that x 2 + y 2 = 69. In this problem: x and y measure the positions of two moving objects, both in miles. t is time, measured in hours. Find when x = 5 miles and = 60 mph. Assume y > 0.

2 4. /2 points h is measured in inches and is a function of time, t. V is measured in in and is a function of time, t r = inches and is constant. Find when = 0 in /min. 5. /2 points Suppose that V = lwh. In this problem: h is measured in feet and is a function of time, t. V is measured in ft and is a function of time, t l = feet and w = 2 feet, both constant. Find when = 0. ft/min. Give an exact decimal answer with correct units. 6. /2 points h is measured in inches and is a function of time, t. V is measured in in and is a function of time, t r is also a function of time. dr Find when h = 6 in, r = 2 in, =.2 in/min, and = 0.4 in/min.

3 7. /2 points 0 Suppose that tan θ =. In this problem: y y and θ are functions of time t. y is measured in feet;; θ in radians. [Note: radians are dimensionless units. You can write θ with no units and it is considered correct, although hard to read.] t is measured in hours. dθ π = radians/hr. 2 [Note: These units are typically written as /hr or hr. ] Find when θ π = /2 points x Suppose that sin θ =. In this problem: z x, z and θ are all functions of time, t. x and z are measured in miles;; θ in radians, and t in hours. = 60 mph. dθ dz Find when x = 2 miles, z = 5 miles, and = 55 mph. Be accurate to decimal place and include correct units. See previous problem for how to write the units without using the word "radians". 9. /2 points Suppose that x 2 + y 2 = z 2, with all of x, y, and z measured in miles. dz Find when x = 5 miles, y = 0 miles, = 20 mph, and = 0 mph. Assume z > 0.

4 0. /2 points V, h and r are all functions of time, t. h and r are measured in inches;; V in in ;; t in minutes. r = 4h. Find when h = inches and = 0 in /min. Be accurate to 4 decimal places and include correct units.. / points Suppose that x and y are all functions of time, t. Both x and y are measured in feet. The triangles in the figure below are similar, and Create your own equation that involves x and y. Then find when = ft/s.

5 2. / points Suppose that V = lwh. In this problem: 2 V, w and h are all functions of time, t. w and h are measured in feet;; V in ft ;; t in minutes. l = 0 feet and is constant. w and h are related by similar triangles as shown below. Find when w = feet and = 0.2 ft/min.. / points Suppose that x 2 + y 2 = 00. In this problem: y measures the height of an object in feet. x measures the position of a second object in feet. x and y are both positive. t is time in seconds. d 2 x 2 = 2 ft/s 2. Find d 2 y 2 when y = 5 ft and =.5 ft/s. Hint: Refer to Problem to get values for x and.