1.Kite quickly gains altitude (first stage). It hovers for some time, looking for prey (second stage). And then it falls like a stone. At what stage of the hawk's movement does the force of gravity act on it?

1)Only at the first stage 3)Only at the third stage

2)Only at the second stage 4) At all three stages

2.What is the force of gravity acting on a hare weighing 7 kg?

1)0.7 N 2) 7 N 3) 70 N 4) 700 N

3. Which statement(s) are true?

A: the acceleration of gravity is greater at the Earth’s pole B: the acceleration of gravity is greater at equatorial latitudes

1) Only A 3) Both A and B

2) Only B 4) Neither A nor B

4. The radius of a certain planet is equal to the radius of the Earth, and its mass is 3 times greater than that of the Earth. Determine the acceleration of gravity on the surface of this planet. The acceleration of free fall on the Earth's surface is 10 m/s 2.

1) 3.3 m/s 2 3) 30 m/s 2

2) 10 m/s 2 4) 90 m/s 2

5. The mass and radius of a certain planet are 2 times greater than that of the Earth. Determine the acceleration of gravity on the surface of this planet. The acceleration of free fall on the Earth's surface is 10 m/s 2.

2.5 m/s 2 2)5 m/s 2 3) 10 m/s 2 4) 20 m/s 2

6. How will the acceleration of gravity change when rising to a height equal to 2 radii of the planet?

1) Will decrease by 2 times

2) Will decrease by 3 times

3) Will decrease by 9 times

4) Will increase 9 times

7. What is the acceleration due to gravity at a height equal to half the Earth's radius? The acceleration of free fall on the Earth's surface is 10 m/s 2.

1)20 m/s 2 3) 5 m/s 2

2)10 m/s 2 4) 4.4 m/s 2

8. At the Earth's surface, a gravitational force of 720 N acts on an astronaut. What force of gravity acts on the Earth's side on the same astronaut in a spacecraft moving in a circular orbit around the Earth at a distance of one Earth's radius from its surface?

1)360 N 3) 180 N

2)240 N 4) 80 N

9. A space rocket is moving away from the Earth. At what distance from the earth's surface will the force of gravitational attraction of the rocket by the Earth decrease by 4 times compared to the force of attraction on the earth's surface? (Distance is expressed in Earth radii R.)

1)R 3) 2R

2)P/2Ya 4) 3 R

Let's forget for a while all the aerial maneuvers such as turns, takeoffs and landings. Active flight, in which the falcon propels itself forward by flapping its wings, has several recognizable types. The first is a measured flight, more or less comparable to our walking. Research Spedding, Pennycuick and Rayner showed that when a falcon, such as a kestrel or peregrine falcon, flies very slowly, at a speed of less than three meters per second, the upward movements of the wings are passive, providing no lift or creating vortices. The result is toroid-shaped vortex rings created by shocks from the downward movements of the wings (Figure 1.16. 1). When flapping, the wing bends very close to the body and tucks in without creating wake vortices of air.

Buzzards and eagles fly in a similar way, but their wingbeats are deeper and slower, and their wings fold more strongly. Their wings move up faster than down. In strenuous flight, it is likely that the flapping becomes active, providing some lift, while in slower flight, it is likely to be passive. When the falcon reaches speeds above 7 meters per second, the airspeed is sufficient to raise the wings, which reduces the load on the suprascapular muscles. When the flapping is active, it creates wake vortices (Figure 1.16.2). Instead of folding close to the body, the wing is held stiffer and straighter as it flaps, resulting in the typical flickering flight of a cruising peregrine falcon (Figure 1.16.3).

A falcon that flies at such a high speed that normal cruising wingbeats will only slow down its flight is like a cyclist who cannot pedal fast enough to accelerate. Therefore, the falcon glides through the air with its wings half-closed, with the secondary ones providing lift while otherwise minimizing the leverage load on the pectoral muscles. Wake vortices softly fly off from behind (in the center, Figure 1.16.4) as during steep gliding (compare Figures 1.15.2 and 3). The falcon then performs a series of deep, pulsating strokes in which it puts as much force as possible into several rapid drops of the wing, faster than its flight speed, and which are aimed to provide propulsion rather than lift. The result, which is very noticeable in the gyrfalcon in sprint flight, is that each flap of the wings clearly jerks the bird forward. It looks like someone invisible is kicking the bird from behind. Even a small series of such pulsating flaps is enough for the falcon to gain such speed that further flapping of its wings is useless. By then something will happen.

Hawks are also capable of sprinting flight, but they have a slightly different problem. While large falcons need to cover long distances very quickly, hawks need to fly short distances very quickly. They can win or lose a fight in a matter of seconds. Therefore, they have problems not with highest speed, but with acceleration. Hawks begin sprinting from a static position or during slow flight. Therefore, their sprint must start almost from scratch. While the gyrfalcon is like a cyclist who wins a long-distance race through top speed, the hawk is like a cyclist waiting to start a 50-meter race. Perhaps he won’t even have time to reach his maximum speed by the finish line. Consequently, he needs to give his all in a short period of time, so he cannot waste half of that time on useless wing lifts that do not contribute to the thrusts. He solves this problem by using elastic wings with cutouts on the primary, which not only accumulate energy, but also reduce the braking effect during the flapping.

When the wing is lowered (Fig. 1.16.5 a-f), a push and lift are created, but the wing is very short, which gives the pectoral muscles technical advantage, the tips of the primary ones bend back to the place where their angle of inclination reaches 90 degrees to the surface of the wing vertically and horizontally (Fig. 1.16.5 f). The bird then begins to create thrust with its wings, actively using the suprascapular muscles (1.16.5 f). The elastic primaries begin to regain their normal shape by pushing air down and back, which provides lift and propulsion and also provides assistance to the suprascapular muscles. The wing is now halfway back and half folded. The edges of the primary are pointed forward and aligned with the angle of incidence. At the top of the stroke they come together and again provide a push when the wing is lowered.

Assuming active flight in still air and at the same level, we can construct approximate acceleration curves for various predators. Unable to compare data on birds of prey, I compiled these curves from several sources, mainly from the works N. J. Slijper and T. A. M. Jack, as well as from my own observations. Although they may not be very accurate for absolute speed, they do give an idea of ​​the differences between species, although of course individual differences between birds are quite significant.

The common buzzard (Figure 1.16.6) is a relatively poor active flyer. It accelerates slowly, has a low top speed, and soon runs out of steam. It is rare to see a buzzard fly more than 100 m in a spriter's flight, and very rarely 200 meters. He soon begins to rest, gliding between strokes, on the chart this starts at 40 meters. When flying horizontally, it can gain speed up to 10 meters per second, making about 5-6.5 beats per second. There are few prey that move slowly enough to motivate a buzzard to exert effort longer than 80 meters. Most of the prey will either be quickly caught (for example, voles) or will leave the buzzard when chased
far behind (for example, partridge). In such cases, the buzzard lags behind and sits somewhere, in in this case at 45 meters.

Small hawks, such as the sparrowhawk, on the contrary, develop maximum speed in less than a second, in the first meters. Their explosive sprinting gives them an advantage over all other listed predators. However, few maintain a sprint at top speed for more than 100 m. By this time the flight usually ends one way or another, and if it was successful, then the sparrowhawk lands after about 150 meters.

Studying the goshawk Slijper found that males start faster, but after about 70 meters the females overtake them. Once on the wing, females fly a little faster. After about 130 meters, goshawks usually slow down. If they fail to catch the prey at the beginning of the sprint, they give up the pursuit or fly by inertia, gaining altitude and tracking the prey.

At the first 20 meters, the peregrine falcon flies not much faster than the buzzard, but at 50 meters it begins to pick up speed, at about 130 meters it overtakes the goshawk and maintains good speed within several hundred meters. In a horizontal flapping flight over a long distance, it will probably only be overtaken by a gyrfalcon.

The New Zealand falcon, with its hawk-like profile and falcon-like physiology, starts out more like a small male goshawk. By the time the female sparrowhawk has flown 80 meters, the falcon has flown 100 meters. At about 130 meters, when the goshawk begins to slow down, the speed of the New Zealand falcon remains the same, but it is overtaken by the peregrine falcon, which has picked up speed. By the time the peregrine falcon reaches 280 meters, the New Zealand falcon will be about 40 meters behind, and both will disappear over the horizon without signs of fatigue.

Acceleration and maximum speed in predators, when pursuing, should be comparable to these parameters of their prey. The quail has a similar flight pattern to the sparrowhawk, the pheasant to the goshawk, and pigeons (albeit slightly faster at takeoff) to the peregrine falcon. Hawks quickly drop strong prey capable of long flight, unless they catch it while sprinting or attacking from an ambush.

The effect of the explosive start of the hawks is manifested in the increase in speed in the first 40 meters. Cooper's hawks, for example, typically make 4-5.5 beats per second, and at takeoff 7-8 beats per second, using the pectoral muscles, which make up about 17% of the total body weight. He will cover this distance when the buzzard and most falcons fly only 20 meters. Their mastery of distance traversing lies in the ability to make a direct flying attack (see 6.10) and the ability to judge the maximum distance at which it is advisable to attack the intended prey. Large falcons usually do not make short direct attacks, but prefer more predictable long ones. Whenever possible, buzzards do not use sprint flight at all, instead they use an altitude that allows them to attack from a glide or dive.

In addition to the endless transformations of acceleration curves and attack distances, there is the problem of maneuverability. Here the highest indicators are for hawks, merlin and New Zealand falcon; Large falcons and Harris's hawks are less agile and more bulky in the tail than buzzards. Prey also vary greatly in maneuverability (see section 7.4). Usually the price of greater maneuverability is a lower top speed; a long tail promotes agility but creates a braking effect.

Chapter 1. Laws of interaction and motion of bodies

Acceleration of free fall on Earth and other celestial bodies

1. The hawk quickly gains altitude (first stage). Soars for some time, looking for prey (second ethane). And then it falls like a stone. At what stage of the hawk's movement does the force of gravity act on it?

1) Only at the first stage
2) Only at the second stage
3) Only at the third stage
4) At all three stages

2. What is the force of gravity acting on a hare weighing 6 kg?

1) 0.6 N
2) 6 N
3) 60 N
4) 600 N

3. What formula can be used to determine the acceleration of gravity on the surface of the planet?

4. Which statement(s) is true?

A: free acceleration, fall is greater at the Earth's pole
B: gravitational acceleration is greater at equatorial latitudes

1) Only A
2) Only B
3) Both A and B
4) Neither A nor B

5. The radius of a certain planet is equal to the radius of the Earth, and its mass is 3 times greater than that of the Earth. Determine the acceleration of gravity on the surface of this planet. The acceleration of free fall on the surface of Zenshi is 10 m/s 2 .

1) 3.3 m/s 2
2) 10 m/s 2
3) 30 m/s 2
4) 90 m/s 2

6. The mass and radius of a certain planet are 2 times greater than that of the Earth. Determine the acceleration of gravity on the surface of this planet. The acceleration of free fall on the Earth's surface is 10 m/s 2.

1) 2.5 m/s 2
2) 5 m/s 2
3) 10 m/s 2
4) 20 m/s 2