Before the driver applies the brakes ( with the reaction time ):
d 1 = v0 · t = 20 m/s · 0.53 s = 10.6 m
After that:
v = v0 - a · t1
0 = 20 m/s - 7 · t1
7 · t1 = 20
t1 = 2.86 s
d 2 = v 0 · t1 - a · t1² / 2
d 2 = 20 m/s · 2.86 s - 7 m/s² · (2.86 s)²/2 = 57.2 m - 28.6 m = 28.6 m
d = d 1 + d 2 = 10.6 m + 28.6 m = 39.2 m
Answer: the stopping distance of a car is 39.2 m.
The answer would be choice C.
Perpendicular lines cross each other and form a right angle as you can see marked in the third picture.
I believe it's always a parallelogram??
Answer:
$39.60
Step-by-step explanation:
We are finding 66 - 40%
66 less 40% = 60% of 66
60% of 66 is the price of the item now.
Convert 60% to decimal form by dividing by 100.
60%/100 = 0.60
Multiply the decimal form by 66
66 X 0.6 = 39.60
Since we are dealing with money, keep 2 decimal places, even if the last digit is 0.
The price of the item now is $39.60.
Use the 2 points to find the gradient of the line
Gradient = (y - y1)/(x - x1), y and y1 are the two different y values.
(2.3 - - 7.4)/(-4.3 - 1.3) = -97/56 = -1.732
Note: y and x both come from the same coordinate, and y1 and x1 also come from the same coordinates - (x , y), (x1 , y1)
Use the following to find the equation (x, x1, y, and y1 are not the same as the first part)
y - y1 = m(x - x1)
Where x2 and y2 is an intersection (one of the coordinates you used) and m is the gradient you found.
So...
y - 2.3 = -1.732(x - - 4.3)
You can simplify this if you are required to.
