A=(v-u)/t
We know a=2.5, v=40, u=10, so:
2.5=(40-10)/t
2.5t=40-10
2.5t=30
Divide both sides by 2.5
t=12 It takes 12 seconds for the car to reach 40m/s

To find out how far it went, you do:
d=v+1/2 at^2
d=10+1/2(2.5)(12)^2
d=10+1/2(2.5)(144)
d=10+(1.25)(72)
d=10+90
d=100m

Hope this helps :)

7 0

3 years ago

A rectangle has an area of 171 square meters. Its width is ten meters less than the length. Find the measures of the length and

9966 [12]

Step-by-step explanation:

The area of a rectangle is 171 m²

Let l is the length and b is the width of the rectangle

It width is 10 m less than the length. So,

b = l-10 ...(1)

Area of a rectangle is given by :

$A=l\times b\\\\171=l(l-10)\\\\l^2-10l=171\\\\l^2-10l-171=0\\\\l^2-19l+9l-171=0\\\\\text{taking common together}\\\\l(l-19)+9(l-19)=0\\\\(l-9)(l-19)=0$

l = 9 m or l = 19 m

If l = 9 m,

b = 9-10 = -1 m (can't be possible)

If l = 19 m

b = 19-10 = 9 m

So, the length an the breadth of the rectangle is 19 m and 9 m respectively.

8 0

2 years ago

How did we transform from f(x) =x2 to g(x) = -3x2

Oksi-84 [34.3K]

Answer:

f(x) is reflected over the x-axis and vertically scaled by a factor of 3

Step-by-step explanation:

If you compare the two functions, you see that ...

g(x) = -3f(x)

Multiplication by -1 effects a reflection over the x-axis. (All y-values are transformed to their opposite.)

Multiplication by 3 is a vertical scaling by a factor of 3.

Taken together, f(x) is reflected over the x-axis and vertically scaled by a factor of 3.

7 0

2 years ago