Question

2.Перевидите значение величин в единицы системы СИ: 59км\ч ,25г,20мм^3 4.Определите за какое время автомобиль ,двигаясь из состояния покоя с ускорением 0.6м/с^2,пройдёт 30 м. 5.Найдите потенциальную и кинетическую энергию тела массой 3 кг,падающего свободного с высоты 5 м,на расстоянии 2 м от поверхности земли. помогите пожалуйста )

Answer 1

2 .
59/ 3,6 =м/с
25*10^-3 кг
20*10^-9 м^3
4.
t^2=2*s/a
t^2=100
t=10c
5.
Eп =mgh1= 3*10*2=60
E=Eп+Eк
Е=mgh=3*10*5=150
Eк=150-60=90

Answer 2

Conversion of Units to SI:

To convert the given values to SI units, we can use the following conversions:

1. 59 km/h: - To convert kilometers per hour (km/h) to meters per second (m/s), we can use the conversion factor of 1 km/h = 0.2778 m/s. - Therefore, 59 km/h is equal to 16.39 m/s.

2. 25 g: - To convert grams (g) to kilograms (kg), we can use the conversion factor of 1 g = 0.001 kg. - Therefore, 25 g is equal to 0.025 kg.

3. 20 mm^3: - To convert cubic millimeters (mm^3) to cubic meters (m^3), we can use the conversion factor of 1 mm^3 = 1e-9 m^3. - Therefore, 20 mm^3 is equal to 2e-8 m^3.

Calculation of Time taken by a Car:

To determine the time taken by a car to travel a distance of 30 m with an acceleration of 0.6 m/s^2, we can use the following kinematic equation:

\[distance = initial velocity * time + (1/2) * acceleration * time^2\]

Given: - Initial velocity (u) = 0 m/s (car starts from rest) - Distance (s) = 30 m - Acceleration (a) = 0.6 m/s^2

Plugging in the values, we can solve for time (t):

\[30 = 0 * t + (1/2) * 0.6 * t^2\]

Simplifying the equation, we get:

\[0.3 * t^2 = 30\]

Solving for t, we find:

\[t^2 = 100\]

\[t = 10\]

Therefore, the car will take 10 seconds to travel a distance of 30 m with an acceleration of 0.6 m/s^2.

Calculation of Potential and Kinetic Energy:

To calculate the potential and kinetic energy of an object, we need to consider the following formulas:

1. Potential Energy (PE): - The potential energy of an object at a certain height is given by the formula: PE = m * g * h, where m is the mass of the object, g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height. - Given: mass (m) = 3 kg, height (h) = 5 m. - Plugging in the values, we can calculate the potential energy: - PE = 3 * 9.8 * 5 = 147 J.

2. Kinetic Energy (KE): - The kinetic energy of an object is given by the formula: KE = (1/2) * m * v^2, where m is the mass of the object and v is the velocity. - Since the object is falling freely, its velocity can be calculated using the formula: v = sqrt(2 * g * h). - Given: mass (m) = 3 kg, height (h) = 5 m. - Plugging in the values, we can calculate the velocity: - v = sqrt(2 * 9.8 * 5) ≈ 9.9 m/s. - Now, we can calculate the kinetic energy: - KE = (1/2) * 3 * (9.9)^2 = 145.53 J.

Therefore, the potential energy of the object is approximately 147 J and the kinetic energy is approximately 145.53 J when it falls freely from a height of 5 m and is 2 m above the ground.