Question

Домашнее задание 7 класс 9.02.22 1. Человек масса которого 80 кг держит в руках ящик массой 15 кг. Определите силу тяжести и вес человека. 2. На сколько удлинится рыболовная леска жесткостью 0,5 кН/м при равномерном поднятии вертикально вверх рыбы массой 200 г. 3.Последние исследования палеонтологов показали. Что самый крупный ископаемый ящер - сейсмозавр (сотрясатель земли) имел массу 40 т. Определите его вес. 4. Каков коэффициент жесткости берцовой кости, если масса человека 80 кг, а кость сжимается на 0,03 мм? 5. На тело действуют две силы: влево, равная 10 Н, и вправо, равная 16 Н. куда направлена равнодействующая этих сил​

Answer 1

Ответ:

1 Задача

Дано:

m1=80кг

m2=15кг

Fт-?

Решение:

m1+m2=95

Fт=mg=10*95=950(H)

Отв:950(Н)

2 Задача

Дано:

K-0.5кН=500Н

m=200г-0.2кг

l-?

Решение:

l=F:K=0.2:500H/м=4мм

Отв:4мм

Задача 3

Дано:

m=40т=40000кг

F-?

Решение

F=mg=40000*10=400000Н=400К/Н

Отв:400 К/Н

Задача 4

Дано:

m=80кг

l-0.03

k-?

Решение:

K=(80*10):0.0003=2.6 МН/м

Задача 5

Дано

F1=10H

F2=16H

Решение:

F=16-10=6 H

Отв:6 Н,вправо

Объяснение:

Answer 2

1. Force and Weight Calculation

To determine the force of gravity and the weight of the person holding a 15 kg box, we can use the following formulas:

Force of Gravity (Fg) = mass × acceleration due to gravity (g)

Weight = mass × acceleration due to gravity (g)

Given: - Mass of the person (m1) = 80 kg - Mass of the box (m2) = 15 kg - Acceleration due to gravity (g) = 9.8 m/s^2

Using the above information, we can calculate the force of gravity and the weight of the person.

The force of gravity acting on the person is the force exerted by the Earth's gravitational pull on the person's mass. It can be calculated using the formula: Fg = m1 × g

The weight of the person is the force with which the person is pulled towards the center of the Earth due to gravity. It can be calculated using the formula: Weight = m1 × g

Let's calculate the force of gravity and the weight of the person: - Force of Gravity (Fg) = 80 kg × 9.8 m/s^2 - Weight = 80 kg × 9.8 m/s^2

[[1 #]]

2. Extension of Fishing Line

To calculate the extension of the fishing line when lifting a fish vertically upwards, we can use Hooke's Law, which states that the extension of an elastic object is directly proportional to the force applied to it.

The formula to calculate the extension (ΔL) is: ΔL = (F × L) / (k × A)

Where: - F = Force applied (in newtons) - L = Original length of the fishing line (in meters) - k = Spring constant (in newtons per meter) - A = Cross-sectional area of the fishing line (in square meters)

Given: - Spring constant (k) = 0.5 kN/m (0.5 kilonewtons per meter) - Force applied (F) = 200 g (0.2 kg) × 9.8 m/s^2 (to convert mass to force) - Original length of the fishing line (L) = ?

Let's calculate the extension of the fishing line using the provided information.

[[2 #]]

3. Determining the Weight of the Seismosaurus

To determine the weight of the Seismosaurus, we can use the formula: Weight = mass × acceleration due to gravity (g)

Given: - Mass of the Seismosaurus = 40,000 kg - Acceleration due to gravity (g) = 9.8 m/s^2

Let's calculate the weight of the Seismosaurus using the provided information.

[[3 #]]

4. Coefficient of Bone Stiffness

To calculate the coefficient of stiffness of the tibia bone, we can use the formula: Stiffness = (Force × Length) / (Displacement × Area)

Given: - Mass of the person (m) = 80 kg - Displacement of the bone (Δx) = 0.03 mm (convert to meters) - Force applied (F) = ? - Length of the bone (L) = ? - Area of the bone (A) = ?

Let's calculate the coefficient of stiffness of the tibia bone using the provided information.

[[4 #]]

5. Resultant Force Direction

To determine the direction of the resultant force acting on the body due to the two forces, we can use vector addition.

Given: - Force to the left = 10 N - Force to the right = 16 N

Let's calculate the direction of the resultant force due to the two given forces.

[[5 #]]