This is the concept of trajectories;
We are required to calculate the time taken for the base ball whose distant to reach the maximum height has been modeled by h=-16t^2+64t+4.2 took to hit the ground. Here we proceed as follows;
At the time when the base ball hits the ground the height,h=0
Thus;
-16t^2+64t+4.2=0
this is a quadratic equation, to solve the quadratic equation we use the formula;
t=[-b+/- sqrt(b^2-4ac)]/(2a)
where;
a=-16,b=64, c=4.2
thus substituting the values in our formula we get:
t=[-64+/-sqrt(64^2-4*(-16)*4.2)]/(-16*2)
t=[-64+/- sqrt(4364.8)]/(-32)
t=[-64+/-66.1]/(-32)
t=4.1 or-0.1
thus the we take the positive value t=4.1 and we conclude that the time taken for the ball to hit the ground was 4.1 seconds
Hi there! 3 feet = 1 yard, 12 inches = 1 foot and 36 inches = 1 yard. All we have to do is change them up into different units by doing a bit of multiplication, division, maybe mental math, and even proportions if you know how to do them. Regardless on what you do, if you do it correctly, here are what your answers should be for each unit.
Inches
Carol: 42 inches
Tino: 30 inches
Baxter: 54 inches
Feet:
Carol: 3.5 feet
Tino: 2.5 feet
Baxter: 4.5 feet
Yards:
Carol: 1 1/6 yards
Tino: 5/6 yards
Baxter: 1 1/2 yards
Answer:
9 1/5
Step-by-step explanation:
3 2/7 * 2 4/5
Change to improper fractions
( 7*3+2)/7 * ( 5*2+4)/5
23/7 * 14/5
Rewriting
14/7 * 23/5
2 * 23/5
46/5
Changing back to a mixed number
5 goes into 45 9 times with 1 left over
9 1/5
To subtract? as minus means subract/take away?
