Let us examine the given situations one at a time.
Case a. A 200-pound barbell is held over your head.
The barbell is in static equilibrium because it is not moving.
Answer: STATIC EQUILIBRIUM
Case b. A girder is being lifted at a constant speed by a crane.
The girder is moving, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case c: A jet plane has reached its cruising speed at an altitude.
The plane is moving at cruising speed, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case d: A box in the back of a truck doesn't slide as the truck stops.
The box does not slide because the frictional force between the box and the floor of the truck balances out the inertial force. The box is in static equilibrium.
Answer: STATIC EQUILIBRIUM
Answer:
They are the smallest pancise of any matere
Answer:
- <u>Because in both kind of motions, the position is periodically repeated. Both are simple harmonic motions.</u>
Explanation:
<em>Moving back and forth</em> means that the moving object goes through the same position every time a certain period of time elapses.
The same is true for the <em>circular motion</em>, every time the object completes a turn, the object is in the same position.
They are examples of simple harmonic motions. The time it takes the object to repeat a complete cycle is called period.
Therefore, in a grahp of position versus time, the curve that represents the position repeats itself every so often equal to one period, both for moving back and forth and for moving in a circle.
Reaction time will stay the same for each person however the faster the car is going the faster someones reaction time would need to be react to something that happened. therefore it might seem like someone had a slower reaction time when a car is moving faster because everything happens faster when you are moving faster
I hope I've helped!