Answer:
c) 1.0 kg
Explanation:
The mass of the stick will be located at the centre of the metre rule. Since the rock is located 0.25m from the pivot, the mass of the meter rule is also 0.25m to the Right of the support
According to law of moment
Sum of clockwise moment = sum of anti clockwise moments
Clockwise moment = M×0.25(mass of metre rule is M)
CW moment = 0.25M
Anti clockwise moment = 0.25×1
ACW moments = 0.25kgm
Equate;
0.25M = 0.25
M = 0.25/0.25
M = 1.0kg
Hence the mass of the metre rule is 1.0kg
Apparent magnitude means how bright a star APPEARS to us on Earth. It can be affected by ...
... how bright the star really is
... how far the star is from us
... how much gas and dust is between us
... how much of the star's total output is in visible light
<span>Artificial fertilizers are made chemically. They emphasize three main</span>
Answer:
The evolutionary success of bats is accredited to their ability, as the only mammals, to fly and navigate in darkness by echolocation, thus filling a niche exploited by few other predators. Over 90% of all bat species use echolocation to localize obstacles in their environment by comparing their own high frequency sound pulses with returning echoes. The ability to localize and identify objects without the use of vision allows bats to forage for airborne nocturnal insects, but also for a diverse range of other food types including motionless perched prey or non-animal food items.
The agility and precision with which bats navigate and forage in total darkness, is in large part due to the accuracy and flexibility of their echolocation system. The echolocation clicks of the few echolocating Pteropodidae (Rousettus) are fundamentally different from the echolocation sounds produced in the larynx that we focus on here, and thus not part of this review. Many studies have shown that bats adapt their echolocation calls to a variety of conditions, changing duration and bandwidth of each call and the rate at which calls are emitted in response to changing perceptual demands . In recent years the intensity and directionality of echolocation signals has received increasing research attention and it is becoming evident that these parameters also play a major role in how bats successfully navigate and forage. To perceive an object in its surroundings, a bat must ensonify the object with enough energy to return an audible echo. Hence, the intensity and duration of the emitted signal act together to determine how far away a bat can echolocate an object. Equally important is signal directionality. Bat echolocation calls are directional, i.e., more call energy is focused in the forward direction than to the sides (Simmons, 1969; Shimozawa et al., 1974; Mogensen and Møhl, 1979; Hartley and Suthers, 1987, 1989; Henze and O'Neill, 1991). An object detectable at 2 m directly in front of the bat may not be detected if it is located at the same distance but off to the side. Consequently, at any given echolocation frequency and duration, it is the combination of signal intensity and signal directionality that defines the search volume, i.e., the volume in space where the bat can detect an object.
The aim of this review is to summarize current knowledge about intensity and directionality of bat echolocation calls, and show how both are adapted to habitat and behavioral context. Finally, we discuss the importance of active motor-control to dynamically adjust both signal intensity and directionality to solve the different tasks faced by echolocating bats.
Explanation:
The characteristics of the diffraction phenomenon allow to find the result for the shape of the points of light that you pass the tree is:
-
The shape of the dots is circular because it is in the range of far-field diffraction.
Diffraction is the phenomenon where the undulatory part of the light becomes evident, it is the interference of the waves that make up each ray of light, for this phenomenon to occur it must be fulfilled that the wavelength is of the order of the space where pass the light.
In the leafy tree it has many leaves, but there are spaces between them, some of these spaces are small and it fulfills the diffraction condition, therefore we see bright spots and not a continuous shadow.
Diffraction can be classified depending on the distance to the observer:
- Near field or fresnel. In this case the distance from the observer is small and we can see the shape of the object that creates the diffraction.
- Far field or Fraunhoger. In this case the distance between the obstacle (leaves) and the person is great, here the information on the shape of things is lost and we have two observable forms. Lines for the case of slits and circles for the case of objects with a closed shape.
In this case, the distance from the leaves to the observer is large, therefore we are in the case of far-field diffraction and since the edge of the leaves that forms the diffraction is closed, the observable shape is a circle.
In conclusion using the characteristics of the diffraction phenomenon we can find the result for the shape of the points of light that pass the tree is:
-
The shape of the dots is circular because it is in the range of far-field diffraction.
Learn more about diffraction here: brainly.com/question/20140459
