MATH SOLVE

2 months ago

Q:
# I WILL AWARD BRAINLIEST!! PLEASE HELP!!! The figure below shows the movement of a pedestrian from point B to point E. Using the graph, answer the following questions: A) What is the speed of the pedestrian BC, CD, and DE? B) After what time since the stop did he arrive at point E? C) Write the formulas for function d(t) for sections BC, CD, and DE

Accepted Solution

A:

A) The speed of the pedestrian BC is 5 km/h The speed of the pedestrian CD is 0 km/h The speed of the pedestrian DE is 5 km/hB) He arrived E since the stop after 6 hours C) The formula for section BC is d(t) = 40 - 5t The formula for section CD is d(t) = 20 The formula for section DE is d(t) = 50 - 5tStep-by-step explanation:A)In the time-distance graph the speed is the rate of change of distanceand that mean speed = Δd/Δt ⇒ (slope of the line)In line BC:1. Δd = 40 - 20 = 20 km2. Δt = 4 - 0 = 4 hours3. The speed = 20 ÷ 4 = 5 km/hThe speed of the pedestrian BC is 5 km/h In line CD:1. Δd = 20 - 20 = 0 km2. Δt = 6 - 4 = 2 hours3. The speed = 0 ÷ 2 = 0 km/hThe speed of the pedestrian CD is 0 km/hIn line DE:1. Δd = 20 - 0 = 20 km2. Δt = 10 - 6 = 4 hours3. The speed = 20 ÷ 4 = 5 km/hThe speed of the pedestrian DE is 5 km/hB)∵ He stop at t = 4 hours ∵ He arrived at point E at t = 10 hours∵ 10 - 4 = 6 hoursHe arrived E since the stop after 6 hours C)The speeds are represented by linesThe form of the equation of a line is f(x) = mx + c, where m representsthe slope of the line and c is the y-intercept (y when x = 0)1. f(x) is d(t) 2. m is the speed3. x is t4. You can find c by substitute d and t by any point on the lineLine BC Line BC has negative slope because d decreases when t increases∵ m = -5 and c = 40∴ d(t) = 40 - 5tThe formula for section BC is d(t) = 40 - 5tLine CDLine CD is a horizontal line (equation any horizontal line is y = c)∴ m = 0 and c = 20∴ d(t) = 20The formula for section CD is d(t) = 20Line DE Line DE has negative slope because d decreases when t increases∵ m = -5∴ d(t) = -5t + cTo find c substitute the coordinates of point D in the equation∵ The coordinates of point D are (6 , 20)∴ 20 = -5(6) + c∴ 20 = -30 + cAdd 30 to both sides∴ c = 50∴ d(t) = 50 - 5tThe formula for section DE is d(t) = 50 - 5tLearn more:You can learn more about the distance, speed, and time inbrainly.com/question/5102020#LearnwithBrainly