Answer:
(a) 
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:

where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:

(b)
Now, for 90% radiator blackbody at 2000 K:

<u>P = 0.816 Watt</u>
B. As job efficiency increases, stress levels decline (THIS IS WRONG)I think its between A. As job efficiency decreases, stress levels increaseD. As stress levels increase, job efficiency increases
Answer:
Yes, if the two carts are moving into opposite directions
Explanation:
The total momentum of the system of two carts is given by:

where
m1, m2 are the masses of the two carts
v1, v2 are the velocities of the two carts
Let's remind that v (the velocity) is a vector, so its sign depends on the direction in which the cart is moving.
We want to know if it is possible that the total momentum of the system can be zero, so it must be:

From this equation, we see that this condition can only occur if v1 and v2 have opposite signs. Opposite signs mean opposite directions: therefore, the total momentum can be zero if the two carts are moving into opposite directions.
Answer: Eat only when you're truly hungry instead of when you are tired, anxious, or feeling an emotion besides hunger.
Plan meals ahead of time to ensure that you eat a healthy well-balanced meal.
Keep more fruits, low-fat dairy products (low-fat milk and low-fat yogurt), vegetables, and whole-grain foods at home and at work.
Explanation: