Jeremy sold
18
of the tickets
Let's start by imagining a rock being thrown to the air.
Let's say that going up is the positive direction and so, going down is the negative.
The acceleration is pointing down (because of gravity) so it's always negative. While the rock is going up, it's velocity/speed is positive, but the acceleration is negative.
While the rock is going down, both acceleration and speed are negative.
This shows that the first statemente is true, but the second is false.
You can also think that if you define going DOWN as the POSITIVE direction, you can have both positive acceleration and speed, or positive acceleration and negative speed.
So we want to know what do we need to measure to determine the wavelength of the wave on the image. A wavelength is the distance between peaks of the wave. More generally, the distance on which the wave shape repeats. So on the image we need to measure X to determine the wavelength. So the correct answer is X.
Answer:
7 square units
Step-by-step explanation:
As with many geometry problems, there are several ways you can work this.
Label the lower left and lower right vertices of the rectangle points W and E, respectively. You can subtract the areas of triangles WSR and EQR from the area of trapezoid WSQE to find the area of triangle QRS.
The applicable formulas are ...
area of a trapezoid: A = (1/2)(b1 +b2)h
area of a triangle: A = (1/2)bh
So, our areas are ...
AQRS = AWSQE - AWSR - AEQR
= (1/2)(WS +EQ)WE -(1/2)(WS)(WR) -(1/2)(EQ)(ER)
Factoring out 1/2, we have ...
= (1/2)((2+5)·4 -2·2 -5·2)
= (1/2)(28 -4 -10) = 7 . . . . square units
