Those are the answers for 12,13,14,15
How do you find a percent of a number ? Ex. 8% of 90
2 answers:
You might be interested in
Answer:
These two figures are similar because equals
Step-by-step explanation:
The figures will be similar if their ratios of the two sides are equal. So we need to check the ratios of the figures to see if they are similar or not.
For the smaller figure the ratio is , and for the bigger figure the ratio is
which upon simplification reduces to
.
So we see that the ratios are equal. Thus the figures are similar.
Answer:
-0.133 radians/s is the angle between the ladder and the ground changing when the bottom of the ladder is 8 ft from the wall.
Step-by-step explanation:
Let
x= distance between the wall and ladder
Ф = angle between the ladder and ground
The rate of change is: dx/dt = 0.8 ft/s
We need to find dФ/dt when x = 8 ft/s
From the triangle in the figure we see that:
cos Ф = x/10
=> x = 10 cosФ
Now, the rate of change will be
d(x)/dt = d/dt (10cosФ)
dx/dt = -10 sin Ф dФ/dt
dx/dt = 0.8 (given)
to find dФ/dt
we need to find sin Ф when x = 8
By Pythagoras theorem
(hypotenuse)^2 = (Perpendicular)^2+(base)^2
(10)^2 = (8)^2+ (Perpendicular)^2
100 = 64 + (Perpendicular)^2
=> (Perpendicular)^2 = 100-64
(Perpendicular)^2 = 36
Perpendicular = 6
sin Ф = Perpendicular/hypotenuse
sin Ф = 6/10 = 3/5
Putting values in:
dx/dt = -10 sin Ф dФ/dt
0.8 = -10(3/5) dФ/dt
0.8 = -6 dФ/dt
=> dФ/dt = 0.8 / -6
dФ/dt = - 0.133 radians/s
So, -0.133 radians/s is the angle between the ladder and the ground changing when the bottom of the ladder is 8 ft from the wall.
