question 8 (4 points)

duane and albert have a race. duane starts 5 m ahead of albert and runs forward at a speed of 3 m/s. albert runs forward at a speed of 4.2 m/s.

a. write an expression for duane's position in terms of t and vduane. (hint: set x = 0 at albert's starting point.) (1 point)

a is x=5+3t

b. write an expression for albert's position in terms of t and valbert. (1 point)

x=4.2t

c. at what time does albert catch up to duane? (hint: set the two expressions for position equal to each other and solve for time.) (1 point)

t=4.17 seconds

d. how far from albert's starting point are they when they meet? (1 point)

i solved a, b, c but donot know how to do d

The answer to your question is:

Explanation:

Data

Duane                                          Albert

d = 5 m ;  v = 3 m/s                     v = 4.2 m/s

a)                                                b)

Duane's                                      Albert's

d = 5 + (3)t                                  d = 4.2t

d = 5 + 3t

c)                            5 + 3t = 4.2t

                              4.2t - 3t = 5

                                      1.2t = 5

                                           t = 4.17 s

d)

Duane's

d= 5 + 3(4.17)

d = 17.51 m

Alberts

d = 4.2(4.17)

d = 17.51 m

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.