Jixe Posted September 12, 2007 Report Share Posted September 12, 2007 I'm having trouble understanding some projectile motion. If two projectiles are launched at the same speed but at different angles to the horizontal, the one with a greater angle to the horizontal will have a longer travel time but the same distance as the other one, correct? What was the popular physics experiment about a ball being dropped and a dart being thrown (both at the same height) and both landing at the same time? What is this proving? Was this experiment described correctly? As for the oxygen dissociation curve, it shifts right when there is an increase in H+ concentration and P_CO2 concentration, but why is the curve shifted right in the lungs? Link to comment Share on other sites More sharing options...
avenir001 Posted September 13, 2007 Report Share Posted September 13, 2007 if the projectiles are launched at the same speed but at different angles to the horizontal, u can say that the one with the greater angle to the horizontal will have the greater component of velocity in the vertical direction (ie greater Vy) and therefore its time of flight will be greater (cuz time of flight only depends on initial velocity in the vertical direction). At the same time, the projectile with the greater angle to the horizontal will have a smaller Vx, so even though its time of flight is longer, its range may be the same as the other projectile which has a shorter time of flight but a bigger Vx...remember that range is determined by both time of flight AND Vx. If a ball is dropped from a height h, it will reach the ground at the same time as a bullet shot horizontally from the same height h...this is because Vy is the only factor that determines time of flight...for both the ball and the bullet, Vy is zero even tho their Vx's are different. The oxygen dissociation curve does NOT shift to the right in the lungs...well, as far as i know anyway Link to comment Share on other sites More sharing options...
Alastriss Posted September 13, 2007 Report Share Posted September 13, 2007 I'm having trouble understanding some projectile motion. If two projectiles are launched at the same speed but at different angles to the horizontal, the one with a greater angle to the horizontal will have a longer travel time but the same distance as the other one, correct? What was the popular physics experiment about a ball being dropped and a dart being thrown (both at the same height) and both landing at the same time? What is this proving? Was this experiment described correctly? As for the oxygen dissociation curve, it shifts right when there is an increase in H+ concentration and P_CO2 concentration, but why is the curve shifted right in the lungs? The physics experiment you're talking about is saying that heavier objects do not accelerate faster of their mass. The curve shifts back and forth depending on the tissue it is in -- this is the easiest way you should look at it. When in the lungs, there is less PCO2 and subsequently H+, so the decrease in affinity that this caused on Hb and its binding to Oxygen allows the curve to shift back to the left. Link to comment Share on other sites More sharing options...
Jixe Posted September 13, 2007 Author Report Share Posted September 13, 2007 Thanks for the help! Why according to this java demo, http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/ProjectileMotion/jarapplet.html, is the range greater when the angle to the horizontal is smaller and the launch velocity is the same? Shouldn't the range be the same? Is it because the speed given is only in the x direction? Link to comment Share on other sites More sharing options...
Alastriss Posted September 13, 2007 Report Share Posted September 13, 2007 the range covered is greatest when the angle is 45 degrees, try it out! this is kinda fun actually Link to comment Share on other sites More sharing options...
Jixe Posted September 13, 2007 Author Report Share Posted September 13, 2007 I thought the range would be same if the initial velocity was constant. As avenir states that too: "At the same time, the projectile with the greater angle to the horizontal will have a smaller Vx, so even though its time of flight is longer, its range may be the same as the other projectile which has a shorter time of flight but a bigger Vx...remember that range is determined by both time of flight AND Vx." Link to comment Share on other sites More sharing options...
avenir001 Posted September 14, 2007 Report Share Posted September 14, 2007 the range gets bigger as the angle of elevation goes up from zero to 45 degrees...at 45 degrees, u have maximum range...as the angle of elevation increases from 45 to 90, the range gets smaller...actually it goes like this: angle of elevation....range 0...0 15...x 30....y 45....z 60....y 75...x 90...0 Link to comment Share on other sites More sharing options...
The Law Posted September 14, 2007 Report Share Posted September 14, 2007 gonna have to study this all over again starting in a week or 2 Link to comment Share on other sites More sharing options...
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