Answer:
1.86 s
Explanation:
Given the expression
h(t) = -16t²+ 64...................... Equation 1
Where h = height of the object, t = time it will take the object to hit the ground.
Given: h = 64 foot.
We have to concert from foot to meters
If 1 foot = 0.3048 meters
Then, 64 foot = 0.3048×64 = 19.51 meters.
We substitute the value of h into equation
119.51 = -16t²+64
-16t² = 199.51-64
-16t² = 55.51
t² = 55.51/-16
t² = 3.469
t = √3.469
t = 1.86 s.
Hence it will take the object 1.86 s to hit the ground.
The answer is hydrogen and helium
hope this helped (:
Answer:
<em>Answer: B. $0.78.</em>
Explanation:
<u>Cost of Electricity
</u>
The rate of the cost of electricity is usually expressed in $/kWh or cents/kWh because the consumption of electricity is measured in Kilowatts-hour.
The local power company charges 5.79 cents/kWh.
We are required to calculate the cost to run a 120 W stereo system for 4 hours per day for 4 weeks.
The total consumption time is 4 hours/day * 7 days/week *4 weeks = 112 hours
The total energy consumed is 120 W * 112 h =13,440 Wh.
Converting to kWh: 13,440 Wh/1,000 = 13.440 kWh.
Finally, we multiply by the cost rate: 5.79 cents/kWh * 13.440 kWh = 77.8 cents/100 = $0.78.
Answer: B. $0.78.
Answer:
164.2°
Explanation:
speed of wind (w) = 45 km/h due south
speed of aircraft (a) = 165 km/h
in what direction (in degrees) should the aircraft head in so as to fly due west?
To get the direction the pilot should fly, we can form a triangle with the data available where
- the direction of the wind (due south) serves as the opposite side
- the direction the pilot would have to fly so he can end up at he west serves as the hypothenuse
- θ is the angle between the direction the pilot would have to fly and the direction the pilot wishes to fly.
- the direction the pilot wishes to fly ( west) will serve as the adjacent side
- all this can be seen from the attached diagram.
now sin θ = 
sin θ = 
θ =
0.2728
θ = 15.8°
since we are to use the counter-clockwise from east convention our measurement would have to be taken anticlockwise from the east direction, therefore the direction of the aircraft (Ф) = 180-15.8 = 164.2°
I think answer should be when it starts to break