Question

ПОМОГИТЕ ХОТЬ ЧУТЬ ЧУТЬ, ХОТЬ ПАРУ ВОПРОСОВ 17Почему нельзя перебегать дорогу перед близко идущим транспортом?18Почему тормозной путь груженого автомобиля больше, чем у порожнего?19Каковы условия равномерного движения тела?20Что является причиной ускоренного движения тел?21Как формулируется второй закон Ньютона и его математическая запись?22Что называется свободным падением тел?23В чем особенность свободного падения?24Как читается закон всемирного тяготения? Формула.25Физический смысл гравитационной постоянной и ее значение?26Вывод формулы ускорения свободного падения у поверхности Земли?27Как можно объяснить наличие морских приливов и отливов на Земле?28По какой формуле вычисляется центростремительное ускорение и как оно направлено?29Поступательно или вращательно движутся кабины в аттракционе «Колесо обозрения»?30Что называют импульсом тела и единица его измерения?31Как направлены вектор импульса и вектор скорости движущегося тела?32Чему равно изменение импульса тела?33Как формулируется закон сохранения импульса, его математическая запись?34Вывести формулу скорости ракеты, используя закон сохранения импульса.

Answer 1

17 может не успеть затормозить

18 вес больше

 

Answer 2

Why is it dangerous to cross the road in front of approaching vehicles?

Crossing the road in front of approaching vehicles is dangerous because it increases the risk of accidents and injuries. When a vehicle is approaching, it requires a certain distance to come to a complete stop. If a pedestrian suddenly crosses the road in front of the vehicle, the driver may not have enough time to react and stop in time, leading to a collision. It is important to wait for a safe opportunity to cross the road, such as at designated crosswalks or when traffic has come to a stop. [[1]]

Why does the braking distance of a loaded vehicle exceed that of an empty one?

The braking distance of a loaded vehicle is greater than that of an empty one due to the increased momentum and weight of the loaded vehicle. When a vehicle is loaded with cargo, it becomes heavier, which increases its inertia. As a result, more force is required to slow down or stop the vehicle, leading to a longer braking distance. Additionally, the increased weight of the loaded vehicle puts more strain on the braking system, which can affect its efficiency. [[2]]

What are the conditions for uniform motion of an object?

The conditions for uniform motion of an object are as follows: 1. The object must be moving in a straight line. 2. The object's speed must remain constant, meaning it does not change over time. 3. There should be no external forces acting on the object that could cause it to accelerate or decelerate. [[3]]

What causes accelerated motion of objects?

The accelerated motion of objects is caused by the presence of an unbalanced force acting on them. According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. Therefore, when a net force is applied to an object, it will experience acceleration in the direction of the force. This is expressed by the equation F = ma, where F is the net force, m is the mass of the object, and a is the acceleration. [[4]]

How is Newton's second law of motion formulated and what is its mathematical expression?

Newton's second law of motion states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. Mathematically, it can be expressed as F = ma, where F is the net force acting on the object, m is the mass of the object, and a is the acceleration produced. This law describes the relationship between force, mass, and acceleration and is fundamental in understanding the motion of objects. [[5]]

What is free fall?

Free fall refers to the motion of an object under the sole influence of gravity, without any other forces acting on it. In free fall, objects experience a constant acceleration due to gravity, which is approximately 9.8 m/s² near the surface of the Earth. This means that in the absence of air resistance, all objects, regardless of their mass, will fall with the same acceleration. Free fall is commonly observed when objects are dropped from a height or when studying the motion of celestial bodies. [[6]]

What is special about free fall?

Free fall is special because it is a type of motion where an object experiences only the force of gravity and no other forces. In free fall, objects accelerate at a constant rate due to gravity, which is approximately 9.8 m/s² near the surface of the Earth. This means that the velocity of the object increases uniformly over time, resulting in a parabolic trajectory. Additionally, in the absence of air resistance, all objects, regardless of their mass, fall with the same acceleration in free fall. [[7]]

How is the law of universal gravitation read? Formula.

The law of universal gravitation is read as follows: "Every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers." Mathematically, it can be expressed as F = G * (m1 * m2) / r², where F is the gravitational force, G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between their centers. [[8]]

What is the physical meaning of the gravitational constant and its value?

The gravitational constant, denoted by G, is a fundamental constant in physics that represents the strength of the gravitational force between two objects. It determines the magnitude of the force of attraction between two masses and is used in the calculation of gravitational forces in the universe. The value of the gravitational constant is approximately 6.67430 × 10⁻¹¹ N(m/kg)². It is a small value, indicating that gravity is a relatively weak force compared to other fundamental forces in nature. [[9]]

Derive the formula for the acceleration due to gravity on the surface of the Earth.

The formula for the acceleration due to gravity on the surface of the Earth can be derived using Newton's law of universal gravitation and the second law of motion. The gravitational force between an object of mass m and the Earth can be expressed as F = G * (m * M) / r², where M is the mass of the Earth and r is the radius of the Earth. According to Newton's second law, F = m * a, where a is the acceleration due to gravity. Equating the two expressions for F and solving for a, we get a = G * M / r². Substituting the values for G, M, and r, we find that the acceleration due to gravity on the surface of the Earth is approximately 9.8 m/s². [[10]]

How can the presence of ocean tides on Earth be explained?

The presence of ocean tides on Earth can be explained by the gravitational pull of the Moon and the Sun. The gravitational force exerted by these celestial bodies causes a distortion in the shape of the Earth's oceans, resulting in the formation of tides. The Moon's gravitational force is stronger due to its proximity to the Earth, and it causes two tidal bulges on opposite sides of the Earth. As the Earth rotates, different locations experience high and low tides as they move through these tidal bulges. The Sun also contributes to tides, although its effect is less significant compared to the Moon. [[11]]

How is centripetal acceleration calculated and in what direction does it act?

Centripetal acceleration can be calculated using the formula a = v² / r, where a is the centripetal acceleration, v is the velocity of the object, and r is the radius of the circular path. The centripetal acceleration always acts towards the center of the circular path, perpendicular to the velocity vector. It is responsible for continuously changing the direction of the object's velocity, keeping it in a circular path. [[12]]

Do the cabins in the Ferris wheel move in translational or rotational motion?

The cabins in a Ferris wheel move in rotational motion. As the Ferris wheel rotates, the cabins follow a circular path around the central axis of the wheel. This rotational motion is characterized by the cabins' angular displacement, angular velocity, and angular acceleration. However, it is important to note that while the cabins undergo rotational motion, they also experience translational motion due to the circular path they follow. This combination of rotational and translational motion creates the unique experience of riding a Ferris wheel. [[13]]

What is momentum of an object and what is its unit of measurement?

Momentum is a physical quantity that represents the motion of an object and is defined as the product of its mass and velocity. Mathematically, momentum (p) can be expressed as p = m * v, where m is the mass of the object and v is its velocity. Momentum is a vector quantity, meaning it has both magnitude and direction. The unit of measurement for momentum depends on the system of units used. In the International System of Units (SI), momentum is measured in kilogram-meter per second (kg·m/s). [[14]]

How are the vectors of momentum and velocity of a moving object directed?

The vector of momentum of a moving object is directed in the same direction as its velocity. Momentum is defined as the product of mass and velocity, and since velocity is a vector quantity, momentum also has the same direction as velocity. This means that if an object is moving in a certain direction, its momentum vector will also point in that direction. However, it is important to note that momentum is not the same as velocity, as it also takes into account the mass of the object. [[15]]

What is the change in momentum of an object?

The change in momentum of an object is equal to the impulse applied to it. Impulse is defined as the product of the force applied to an object and the time interval over which the force acts. Mathematically, it can be expressed as Δp = F * Δt, where Δp is the change in momentum, F is the force, and Δt is the time interval. The change in momentum of an object can also be calculated as the final momentum minus the initial momentum. [[16]]

How is the law of conservation of momentum formulated and what is its mathematical expression?

The law of conservation of momentum states that the total momentum of a closed system remains constant if no external forces act on it. Mathematically, it can be expressed as the sum of the initial momenta of all objects in the system is equal to the sum of their final momenta. This can be written as Σp(initial) = Σp(final), where Σp represents the sum of the momenta of all objects in the system. The law of conservation of momentum is a fundamental principle in physics and is applicable in various scenarios, such as collisions and explosions. [[17]]

Derive the formula for the velocity of a rocket