Answer:
one-fourth
Explanation:
In a recent year, over 1 trillion was spent on food in the US, about half of that at grocery stores, and about half for restaurants, food service, and other food outlets. About 250 billion was spent at the four largest grocery chains.
Approximately one-fourth of the nation's food is sold by the four largest grocery chains.
The total distance covered by the person is 12 times the height of each stair:
![\Delta h=12 \cdot 30 cm=360 cm=3.60 m](https://tex.z-dn.net/?f=%5CDelta%20h%3D12%20%5Ccdot%2030%20cm%3D360%20cm%3D3.60%20m)
The work done by the person to climb the stairs is equal to the increase in his gravitational potential energy:
![W= \Delta U=mg \Delta h=(45 kg)(9.81 m/s^2)(3.60 m)=1589.2 J](https://tex.z-dn.net/?f=W%3D%20%5CDelta%20U%3Dmg%20%5CDelta%20h%3D%2845%20kg%29%289.81%20m%2Fs%5E2%29%283.60%20m%29%3D1589.2%20J)
And therefore, the power generated by the person in 12 s is the work done divided by the time taken:
![P= \frac{W}{t}= \frac{1589.2 J}{12 s}=132.3 W](https://tex.z-dn.net/?f=P%3D%20%5Cfrac%7BW%7D%7Bt%7D%3D%20%5Cfrac%7B1589.2%20J%7D%7B12%20s%7D%3D132.3%20W%20%20)
So, the correct answer is B.
Answer:
a) t = 22.5 seconds
b) ![a = 2.96 m/s^{2}](https://tex.z-dn.net/?f=a%20%3D%202.96%20m%2Fs%5E%7B2%7D)
c)
in the same direction of the car.
Explanation:
First of all, let's convert the speed of the car to m/s:
![V_{c}=120km/h*1000m/km *1h/3600s =33.3m/s](https://tex.z-dn.net/?f=V_%7Bc%7D%3D120km%2Fh%2A1000m%2Fkm%20%2A1h%2F3600s%20%3D33.3m%2Fs)
Now, since the police officer catches the car, we know that their position is the same 750m, so:
![X_{p}=X_{c}=V_{c}*t](https://tex.z-dn.net/?f=X_%7Bp%7D%3DX_%7Bc%7D%3DV_%7Bc%7D%2At)
Solving for t, we get:
t=22.5s Solved part a)
For the acceleration:
Replacing values and solving for a:
Solved part b)
For the velocity:
Solved part c)
There are very scarce food resources for the other animals and for the deers themselves which can cause massive death if all of the food is eaten
Answer:
<h2>Focal length</h2>
Explanation:
The Focal length of a lens is the distance from the center of the lens to
its principal focus.