Answer:

Step-by-step explanation:
We have,
Radius of the circle is 12 cm
Arc length, l = 21 cm
It is required to find the central angle of the circle. The formula for the length of an arc of a circle is :

is central angle

So, the angle at the centre of the circle is
.
Well when she hits the water h=0 so
2t^2-t-6=0 factor
2t^2-4t+3t-6=0
2t(t-2)+3(t-2)=0
(2t+3)(t-2)=0, since t>0
t=2 seconds...
However it should be noted that h(t)=-2t^2+t+6 implies that
v(t)=dh/dt=-4t+1 and
a(t)=dv/dt=-4
Since this is a free fall equation, this would suggest that the acceleration due to gravity is -4, whether that is supposed to be -4ft/s^2 or -4m/s^2, it certainly is not on this planet! :D If it is -4ft/s^2 it could be on the Moon or if it is -4m/s^2 it could be on Mars.
50 miles = 1 hour
10 miles = 1/50 x 10
= 1/5 hours
= 12 minutes
It will take him 12 minutes to drive 10 miles.
Answer:
pretty sure its 9 : 4
Step-by-step explanation: