1. What forces act on an airplane to keep it at a level altitude?
2. At higher elevations, the air is less dense than at sea level. Using this information, explain why a baseball travels farther when it is hit in a baseball park in Denver than when it is hit with the same force in a baseball park in New York City.
3. Why are seat belts installed in automobiles, airplanes, and most amusement park rides? Express your answer in terms of the various applied forces.
4. A type of sprinkler consists of curved arms on a spinning wheel. The pressure of the water pushes it out of the arms. Why does the sprinkler turn only when the water is on, and in the direction opposite of that water?
Go to www.scilinks.org and use the SciLinks code: HSM1028 if you need help. Personally, the site confused me and was completely useless and impossible to navigate. Please only answer if you know what you're talking about it. Thanks!
2010-01-13T17:20:50Z
I'm a straight A student by the way. So =p rhys. This 1 assignment I don't do won'te kill me.
Joafu2010-01-13T17:24:39Z
Favorite Answer
1) First Law of Motion; if all forces are in equilibrium, a plane will coast in one direction with constant velocity
2) Application of the First Law of Motion. Air density is essentially how much "stuff" is in the air per unit volume. The stuff collides with whatever tries to move through it; as these collisions add up, it slows the object down; think of air friction. In Denver, there is less density, so less stuff to collide with, so the baseball will be able to travel farther before accumulating enough collisions with air molecules to stop its movement.
3) First Law of Motion again- an object in motion will stay in motion. When your car is going 45 mph, so are you, even though relative to the car you don't feel like you're moving. When your car hits something big enough to stop the movement of the car instantaneously, you are still traveling 45 mph. A seat belt provides a force in the opposite direction to help slow you down with the car, instead of letting you propel through the windshield.
4) Third Law of Motion. To every action there is an equal and opposite reaction. Rockets use this principle to escape Earth's pull. When water is propelled one way, it forces the arm the opposite. Also: think of blowing up a balloon and letting it go. The air is released on direction and forces it in the opposite.
1. What forces act on an airplane to keep it at a level altitude?
The upward lift caused by less air density above the wing than below the wing is balanced with the downward force of the plane's mass multiplied by gravitational acceleration.
2. At higher elevations, the air is less dense than at sea level. Using this information, explain why a baseball travels farther when it is hit in a baseball park in Denver than when it is hit with the same force in a baseball park in New York City.
Decreasing air density at the higher altitude results in less air resistance. With a weaker opposing force, the deceleration of the ball is a slower number so it takes longer for the velocity to reach zero, thus the ball goes further.
3. Why are seat belts installed in automobiles, airplanes, and most amusement park rides? Express your answer in terms of the various applied forces.
When you are thrown against the seat belt, the seat belt develops a tension that opposes and balances out the force of you being thrown into it (this is analogous to the rope you're hanging onto developing a tension that opposes and balances out the force pulling you down towards the snapping crocodile jaws below you...)
4. A type of sprinkler consists of curved arms on a spinning wheel. The pressure of the water pushes it out of the arms. Why does the sprinkler turn only when the water is on, and in the direction opposite of that water?
Because there is almost no friction force, the sprinkler is driven in an "opposite" direction by the force equal to and opposite to the force corresponding to the water leaving the sprinkler.
1. Bernoulli's principle. The shape of air plane wings forces more air below the wing than above, this creates two pockets of air. A high pressure pocket below the wing and a low pressure pocket above. This offsets the weight of the plane and allows it to stay at altitude. However, it does not occur if the plane is not moving which is why planes need to be in a constant state of motion. (Also why they can't fly straight up).
2. Less air resistance. Less density means that the baseball will be slowed down less by the air around it. Also important to note that Denver is above New York in elevation.
3. Basically because if the car ride of plane stops or changes direction suddenly the person will not automatically change direction with it. So without the seat belt if your car stopped you would keep moving at your previous velocity and hit your wind shield and probably go right through.
4. Every action has an equal and opposite reaction? The force of the water being pushed out of the holes on the sprinkler causes a push in the opposite direction. If it was on a straight track it would move straight but it is mounted on an axle of some sort so it rotates.
I may have not answered it the way you needed me to but that is the general ideas behind the answers.
1/ checkout forces acting on an airplane.htm and you will find there are essentially 4. thrust, lift, weight and drag. It shows the forces in appropriate proportions. 2/ Denver is situated at a higher altittude than New York City and the air is less dense; therefore a ball hit out of the park in Denver has less drag than one hit in NYC and will travel further as it has less resistance acting on it. 3/ the seatbelt is a resistive force acting against motional forces. 4/ As the sprinkler arm is mounted on an essentially frictionless plane the force of the water pushing through the holes in the sprinkler creates a negative thrust causing the sprinkler to move in the opposite direction to the applied water pressure.
No situation. the reason factor decelerate and lead to the international is that gravity pulls us down into the earth, and this motives friction between you and the floor. The forc of friction slows you down. while the motor vehicle stops unexpectedly, you have a tendency to proceed to bypass in a without delay line at a relentless speed, and so which you do, till you're stopped via the rigidity of friction from the seat or from hitting the dashboard or something. a similar factor occurs once you're making a turn. in case you ever have from now on physics questions you may digital mail me.