A car braked with a constant deceleration of 64 ft/s2, producing skid marks measuring 50 ft before coming to a stop. How fast was the car traveling when the brakes were first applied?

The initial speed of the car was 80 ft/s.

Step-by-step explanation:

The deceleration is the rate at which the car speed decreases. In this case the speed of the car goes all the way down to 0 ft/s and in order to do that it travelled 50 ft.  So we will call the initial speed at which the car started to brake "v_0" and use Torricelli's equation to find it. The equation is given by:

v^2 = (v_0)^2 + 2*a*S

Where v is the final speed, v_0 is the initial speed, a is the rate of acceleration and S is the space travelled. Using the values that the problem gave to us we have:

0^2 = (v_0)^2 - 2*64*50

0 = (v_0)^2 - 6400

(v_0)^2 = 6400

v_0 = sqrt(6400) = 80 ft/s

Notice that in this case "a" was negative, since the car was decelerating instead of accelerating.

The initial speed of the car was 80 ft/s.

The inicial speed of the car was 80 feet per hour.

Step-by-step explanation:

To solve this problem, we can use Torricelli formula to calculate the inicial speed of the car:

V2 = Vo2 + 2*a*D

where V is the final speed, Vo is the inicial speed, a is the acceleration and D is the total distance travelled.

Using V=0, a=-64 and D=50, we have:

0 = Vo2 + 2*(-64)*50

Vo2 = 2*64*50 = 6400

Vo = 80 ft/s

The inicial speed of the car was 80 feet per hour.

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.

6 meters

step-by-step explanation: