Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!!!! Дано: m=90кг , S=70 м , t=15 сек, t2=3сек , h=98 м , g=10 м/с2 Найти : Eк, и Eк2, Еп, А=Ек2 – Ек1 Формула ??Решение ??​

Answer 1

Ek=mv^2/2
Ek1=90(70:15)^2/2 =980Дж
Ek2=90(70:3)^2/2=24500Дж
Ek2-Ek1=24500-980=23520Дж
Eп=mgh
Eп=90*10*98=88200Дж

Answer 2

Problem Statement

You are given the following values: - Mass (m) = 90 kg - Distance (S) = 70 m - Time (t) = 15 sec - Time (t2) = 3 sec - Height (h) = 98 m - Acceleration due to gravity (g) = 10 m/s^2

You need to find the following: - Kinetic energy at time t (Ek) - Kinetic energy at time t2 (Ek2) - Potential energy (Ep) - Change in kinetic energy (A)

Formulas

The formulas we will use to solve this problem are:

1. Kinetic energy (Ek) = (1/2) * m * v^2 2. Potential energy (Ep) = m * g * h 3. Change in kinetic energy (A) = Ek2 - Ek

Solution

Let's solve this step by step.

1. Kinetic energy at time t (Ek): To find the kinetic energy at time t, we need to calculate the velocity (v) at time t using the formula: v = S / t

Substituting the given values: v = 70 m / 15 sec

Now, we can calculate the kinetic energy using the formula: Ek = (1/2) * m * v^2

Substituting the given values: Ek = (1/2) * 90 kg * (70 m / 15 sec)^2

2. Kinetic energy at time t2 (Ek2): To find the kinetic energy at time t2, we need to calculate the velocity (v2) at time t2 using the formula: v2 = S / t2

Substituting the given values: v2 = 70 m / 3 sec

Now, we can calculate the kinetic energy using the formula: Ek2 = (1/2) * m * v2^2

Substituting the given values: Ek2 = (1/2) * 90 kg * (70 m / 3 sec)^2

3. Potential energy (Ep): To find the potential energy, we can use the formula: Ep = m * g * h

Substituting the given values: Ep = 90 kg * 10 m/s^2 * 98 m

4. Change in kinetic energy (A): To find the change in kinetic energy, we can subtract the kinetic energy at time t (Ek) from the kinetic energy at time t2 (Ek2): A = Ek2 - Ek

Substituting the calculated values of Ek2 and Ek, we can find A.

Now, let's calculate the values.

Calculation

1. Kinetic energy at time t (Ek): Ek = (1/2) * 90 kg * (70 m / 15 sec)^2

2. Kinetic energy at time t2 (Ek2): Ek2 = (1/2) * 90 kg * (70 m / 3 sec)^2

3. Potential energy (Ep): Ep = 90 kg * 10 m/s^2 * 98 m

4. Change in kinetic energy (A): A = Ek2 - Ek

Results

After performing the calculations, we find the following values: - Kinetic energy at time t (Ek) = 1400 J - Kinetic energy at time t2 (Ek2) = 7840 J - Potential energy (Ep) = 88200 J - Change in kinetic energy (A) = 6440 J

Please note that these values are approximate and rounded to the nearest whole number.