Question

show that, for 5 14 years ago

Answer 1

and how can i explain the graph that maybe used to show the speeds at t=5 and t=7 are equal?

Answer 2

is this a part of a larger question?

Answer 3

well its a follow up question from the other oone :S

Answer 4

which other one?

Answer 5

the original question that i asked the other question that i typed in the reply is the follow up qeustion

Answer 6

http://monmouth.monmoodle.co.uk//file.php?file=%2F187%2FMEI%20A-LEVEL%20HOMEWORK%20RESOURCES%2FM1%2FM1%20Chapter%20Assessments%2FCA%20Motion%20Chapter%20Assessment.pdf
its question 5

Answer 7

ok thank you! finally we are getting somewhere

Answer 8

:)
soz :S

Answer 9

okay. so you have to show that the acceleration follows
a = -5t +30 for 5<=t<=7

Answer 10

notice from the graph that the acceleration is a straight line with a steep negative slope between 5s and 7s

Answer 11

the slope of the curve is vertical/horizontal
that is -5/1 = -5
with me so far?

Answer 12

also, since it is a straight line, the general form of the expression for acceleration is
a = mt+b
where a is the acceleration, m is the slope and b is the y intercept.

Answer 13

we found that the slope is -5
so a = -5t + b

Answer 14

now, to find b, we substitute a point on the line in the above equation.
at t = 6s, acceleration is 0
so substituting this point we get
0 = -5(6)+b
b - 30 = 0
b = 30.
so the equation of the acceleration curve between t = 5s and t = 7s is
a = -5t+30

Answer 15

THANKS!!! :)

Answer 16

wait so how can i explain the graph that maybe used to show the speeds at t=5 and t=7 are equal?