Answer:
D = 9.9 10⁶ mi
Explanation:
In the exercise they give the expression for maximum viewing distance
D = 2 r h + h²
Ask for this distance for a height of 1100 feet
Let's calculate
D = 2 3960 1100 + 1100²
D = 8.712 10⁶ + 1.21 10⁶
D = 9.92 10⁶ mi
D = 9.9 10⁶ mi
The correct answer is A. B. C. Hope this helps!!
PE=mgh
180=0.5*10*h
180=5h
h=180/5=36 m
Convection currents in the mantle
Explanation:
2. No, not always. Normal force is equal to force of gravity only when there's no acceleration in the vertical direction.
For example, when you stand in an elevator that's not moving, or moving at constant speed, then the normal force equals your weight. But when the elevator accelerates upward, the normal force increases (making you feel heavier). And when the elevator slows down, the normal force decreases (making you feel lighter).
3. Yes, it is possible for an object to be moving eastward and experience a net force westward. An example is a car applying the brakes.
4. Friction force allows you to walk. When you push against the floor, the floor's friction pushes back, as Newton's third law says.
If you try to walk on a slippery surface like ice, you won't be able to push against the ice, and the ice won't push back.
