Which of the following statements is true?
A Newton is equal to 9.8 m/s 2.
On a level surface, applied force equals weight.
Normal forces occur at perpendicular angles to the surface between two objects.
Action-at-a-distance forces require physical contact between objects.
Hurry
A is false. N = kg-m/s^2
C makes no sense at all
D -- contact means no distance, right?
So, B
Normal forces occur at perpendicular angles to the surface between two objects.
..... True
To determine which of the given statements is true, we can analyze and evaluate each statement individually.
1. A Newton is equal to 9.8 m/s^2.
This statement is incorrect. A Newton (N) is the unit of force, whereas meters per second squared (m/s^2) represents acceleration, not force. The correct statement would be: 1 Newton is equal to 1 kilogram meter per second squared (1 N = 1 kg·m/s^2).
2. On a level surface, applied force equals weight.
This statement is true. On a level surface, where there is no vertical acceleration, the applied force acting on an object will be equal to the weight of the object. This can be explained by Newton's second law of motion, which states that the force applied to an object is equal to its mass times its acceleration (F = m·a). When there is no vertical acceleration, the net force acting in the vertical direction is zero, resulting in the applied force being equal to the weight of the object.
3. Normal forces occur at perpendicular angles to the surface between two objects.
This statement is true. In physics, the normal force refers to the force exerted by a surface to support the weight of an object resting on it. The normal force always acts perpendicular (at a 90-degree angle) to the surface between two objects. It counteracts the force applied by the weight of the object, preventing it from sinking into or passing through the surface.
4. Action-at-a-distance forces require physical contact between objects.
This statement is incorrect. Action-at-a-distance forces refer to forces that act on objects even when they are not in physical contact with each other. Examples of such forces include gravitational forces, electrical forces, and magnetic forces. These forces can exert influence on objects without the need for direct contact.
In summary, the correct statements are:
- On a level surface, applied force equals weight.
- Normal forces occur at perpendicular angles to the surface between two objects.