Answer:
12.5 s
Step-by-step explanation:
If acceleration is constant, speed is proportional to time. To increase the speed by 50 km/h, the car will need an additional time given by ...
t/(50 km/h) = (20 s)/(80 km/h)
t = (20 s)(50/80) . . . . . multiply by 50 km/h
t = 12.5 s
It will take 12.5 more seconds for it to reach a speed of 130 km/h.
Answer:
it would be solved by it mom
168cm2
Let r cm be the radius of the balloon, then
<span>2pi(r)=23=>r=23/(2pi) </span>
<span>The surface area= </span>
<span>4pi(r^2)= </span>
<span>4pi[23/2pi)]^2= </span>
<span>(23^2)/pi=168.386 cm^2 </span>
<span>approximately.</span>

To find the gradient of the tangent, we must first differentiate the function.

The gradient at x = 0 is given by evaluating f'(0).

The derivative of the function at this point is negative, which tells us <em>the function is decreasing at that point</em>.
The tangent to the line is a straight line, so we will have a linear equation of the form y = mx + c. We know the gradient, m, is equal to -1, so

Now we need to substitute a point on the tangent into this equation to find c. We know a point when x = 0 lies on here. To find the y-coordinate of this point we need to evaluate f(0).

So the point (0, -1) lies on the tangent. Substituting into the tangent equation: