Krista will have more money in 2 years time than Nick and she will get $14.05 more than Nick. Hope this helps.
Answer:
5a. -0.4 m/s²
5b. 290 m
6. 12.9 s
7. 100 s
8. 17.2 km/hr
Step-by-step explanation:
5. "While approaching a police officer parked in the median, you accelerate uniformly from 31 m/s to 27 m/s in a time of 10 s.
a. What is your acceleration?
b. How far do you travel in that time?"
Given:
v₀ = 31 m/s
v = 27 m/s
t = 10 s
Find: a and Δx
v = at + v₀
(27 m/s) = a (10 s) + (31 m/s)
a = -0.4 m/s²
Δx = ½ (v + v₀) t
Δx = ½ (27 m/s + 31 m/s) (10 s)
Δx = 290 m
6. "If a pronghorn antelope accelerates from rest in a straight line with a constant acceleration of 1.7 m/s², how long does it take for the antelope to reach a speed of 22 m/s?"
Given:
v₀ = 0 m/s
v = 22 m/s
a = 1.7 m/s²
Find: t
v = at + v₀
(22 m/s) = (1.7 m/s²) t + (0 m/s)
t = 12.9 s
7. "A 1200 kg airplane starts from rest and moves forward with a constant acceleration of 5 m/s² along a runway that is 250 m long. How long does it take the plane to travel the 250 m?"
Given:
v₀ = 0 m/s
a = 5 m/s²
Δx = 250 m
Find: t
Δx = v₀ t + ½ at²
(250 m) = (0 m/s) t + ½ (5 m/s²) t²
t = 100 s
8. "During a marathon, a runner runs the first 10 km in 0.58 hours, the next 10 km in 0.54 hours and the last 10 km in 0.62 hours. What is the average speed of the runner during that marathon?"
This isn't a constant acceleration problem, so there's no need for a chart.
Average speed = total distance / total time
v = (10 km + 10 km + 10 km) / (0.58 hr + 0.54 hr + 0.62 hr)
v = 30 km / 1.74 hr
v = 17.2 km/hr
Answer:
(x, y) = (2, -3/4)
Step-by-step explanation:
The point of the "elimination" technique is to combine the equations in a way that eliminates one of the variables. Sometimes this involves multiplying one or both of the equations by constants before you add those results together. In any event, the first step is to look at the coefficients of the variable terms to see if there is a simple combination of them that will result in zero.
The y terms have coefficients that are opposites of each other (4, -4), so you can simply add the two equations to eliminate y as a variable.
(2x +4y) +(x -4y) = (1) +(5)
3x = 6 . . . . . simplify
x = 2 . . . . . . divide by 3
Now, you find y by substituting this value into one of the equations. I would choose the equation with the positive y-coefficient:
2(2) +4y = 1
4y = -3 . . . . . . subtract 4
y = -3/4
Then the solution is ...
(x, y) = (2, -3/4)
_____
A graphing calculator confirms this solution.
Answer: 23
Step-by-step explanation:
1. Divide the amount Lynn paid for the ribbon, 17.25, by the amount the ribbon cost per foot, 0.75, to get how many feet of ribbon she bought.
17.25 / 0.75 = 23
