# Tag Info

30

45 degree angle for a projectile gives you the maximum distance in a vacuum, but air resistance, as pointed out, changes that a little. With air resistance slowing the ball, you need to to throw a tick under 45 degrees for maximum distance. Also Also, since you throw from above the shoulder, not from the ground, the ball is usually thrown a foot or ...

23

I am a baseball fan (and a physicst), and your coach is misleading you a little. First, in the absence of air resistance, a 45-degree launch will get the ball there with miminum energy expenditure. But not, as the other answers suggest, minimum time. And time matters. A lot. :-) Your coach should also be telling you to plan your longer throws such ...

10

Why does my sports coach tell me that when I'm fielding I should throw the baseball 'flat' to get the maximum distance? I thought from physics that you get the most distance from throwing at a 45 degree angle? The second question first, this is true if you are a robot throwing a ball on the Moon (no atmosphere) that releases the ball at the same speed ...

4

Let's analyze with some simplifications. Ignoring friction for a moment... if you throw a ball at angle $\alpha$ with velocity $v$ such that it will fly for a distance $d$, and it is caught at the same height as it is released, then we can quickly calculate the velocity and time of flight. Time of flight: $$t = 2\frac{v_y}{g} = \frac{2v\sin\alpha}{g}$$ ...

4

I am not a baseball expert, but the time, seconds, will maybe matter here. You are correct, the maximum distance, theoretically, is when you throw at a 45 degree angle. However, in baseball you might want the maximum distance compared to how long time it will take. You maybe want the ball to get as far as possible, as fast as possible? This might make your ...

2

A 45 degree angle gives you the maximum distance to the point where the ball first hits the ground. That's not where a baseball will stop. If you hit the ball at a lower angle, more of the total speed will be in the horizontal direction, and the ball will still continue with a fairly high horizontal speed after bouncing. Thus, the point where friction ...

1

RE to your first question - "have a magnet sit inside a solenoid, and apply a specific current through the solenoid, would the magnet be able to be moved outside of the solenoid". This is a yes. If the permanent magnet in the coil is situated off center in the solenoid and the solenoid creates a repulsive field to the field of the permanent magnet, the ...

1

You can actually think of the "little rain drops" that you are picking up as providing some resistance. When you travel at velocity $v$, and have area $A$, you are "picking up" all the material in a cylinder with volume $V=vA$ per unit time. That volume of material needs to be accelerated to velocity $v$, requiring a force $F\Delta t \propto m \Delta v = ... 1 Say the projectile was thrown with a velocity$v$at an angle$\theta$with respect to the horizontal. We ignore all friction effects (air drag, side winds). Define a coordinate system with a vertical$y$-axis, a horizontal$x$-axis and the point of origin$O$the point from which the projectile starts its trajectory. The trajectory can now be decomposed in ... 1 The ball was in flight for four seconds: we can safely say that the ball reached maximum height at$t = 2$. (The gravitational pull is constant and there are no other forces acting, so the flight path is symmetrical). The ball was stationary at$t=2$so its speed is$=0$So now use the formula$v= u + at$, where$a$= acceleration,$t$= time,$u\$= initial ...

1

If this is a correct description of what happens, can we conclude that g does same work on P and on P'? Yes. This is correct. If g acts perpendicularly to the velocity, it performs work of magnitude zero. This is also correct. The reason the two statements above are not contradictory is that the work done by the gravity changes the direction of ...

1

RE to your second query, In all possibility the answer is yes, it will produce a recoil. Apart from the EM fields used up in accelerating the projectile, do realize that the projectile and the gun initially are one system and afterwards the projectile leaves the the projectile-gun system with some energy. This whole scenario is simple classical mechanics. ...

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