Question

ПОМОГИТЕ ПОЖАЛУЙСТА СРОЧНО ДАМ 60 БАЛЛОВ Паровой молот массой 17,2 т падает с высоты 3,6 м на оловянную болванку массой 221 кг. Определи, сколько раз должен упасть молот, чтобы температура болванки поднялась на 46°С, если на нагревание болванки идёт 65 % энергии, выделенной при ударах. Удельная теплоёмкость олова равна 250 Дж/(кг·°С). При расчётах прими g=9,8 Н/кг. (Ответ запиши в виде натурального числа без округления.) Ответ: раз(-а).

Answer 1

Ответ: 7 ударов

Объяснение:

Дано:

m=17,2т=17200кг

h=3,6м

m1=221кг

Δt=46°C

Q=0,65Еп

с=250Дж/кг°С

g=9,8Н/кг

============

n-?

1. Количество теплоты, которое нужно затратить для нагревания болванки на 46°С равно:

Q=c*m1*Δt=250*221*46=2541500Дж

2. Количество теплоты, которое выделяется при одном ударе молота равно:

Q1=0,65Еп=0,65*m*g*h=0,65*17200*9,8*3,6=394430Дж

3. Количество ударов молота равно:

n=Q/Q1=2541500/394430=6,44=7ударов

Answer 2

Problem Analysis

To solve this problem, we need to determine how many times the steam hammer must fall in order to raise the temperature of the lead slug by 46°C. We are given the mass of the steam hammer, the height from which it falls, the mass of the lead slug, the energy transferred to the slug during each impact, and the specific heat capacity of lead.

Solution

To find the number of times the steam hammer must fall, we can use the following steps:

1. Calculate the gravitational potential energy of the steam hammer using the formula: potential energy = mass × gravitational acceleration × height. 2. Calculate the energy transferred to the lead slug during each impact using the formula: energy transferred = energy input × efficiency, where the efficiency is given as 65%. 3. Calculate the total energy required to raise the temperature of the lead slug by 46°C using the formula: total energy = mass × specific heat capacity × temperature change. 4. Divide the total energy required by the energy transferred per impact to find the number of impacts needed: number of impacts = total energy / energy transferred.

Let's calculate the solution step by step.

Step 1: Calculate the gravitational potential energy of the steam hammer

The formula to calculate potential energy is: potential energy = mass × gravitational acceleration × height.

Given: - Mass of the steam hammer (m1) = 17.2 t = 17,200 kg - Height from which it falls (h) = 3.6 m - Gravitational acceleration (g) = 9.8 N/kg

Using the formula, we can calculate the potential energy of the steam hammer: potential energy = 17,200 kg × 9.8 N/kg × 3.6 m.

Let's calculate this value.

Step 2: Calculate the energy transferred to the lead slug during each impact

The formula to calculate the energy transferred is: energy transferred = energy input × efficiency.

Given: - Energy input (E) = energy transferred per impact - Efficiency = 65% = 0.65

Using the formula, we can calculate the energy transferred to the lead slug: energy transferred = E × 0.65.

Step 3: Calculate the total energy required to raise the temperature of the lead slug by 46°C

The formula to calculate the total energy required is: total energy = mass × specific heat capacity × temperature change.

Given: - Mass of the lead slug (m2) = 221 kg - Specific heat capacity of lead (c) = 250 J/(kg·°C) - Temperature change (ΔT) = 46°C

Using the formula, we can calculate the total energy required: total energy = 221 kg × 250 J/(kg·°C) × 46°C.

Step 4: Calculate the number of impacts needed

The formula to calculate the number of impacts needed is: number of impacts = total energy / energy transferred.

Using the values calculated in the previous steps, we can calculate the number of impacts needed: number of impacts = total energy / (E × 0.65).

Let's calculate the solution.

Calculation

Step 1: Calculate the gravitational potential energy of the steam hammer: potential energy = 17,200 kg × 9.8 N/kg × 3.6 m.

Step 2: Calculate the energy transferred to the lead slug during each impact: energy transferred = E × 0.65.

Step 3: Calculate the total energy required to raise the temperature of the lead slug by 46°C: total energy = 221 kg × 250 J/(kg·°C) × 46°C.

Step 4: Calculate the number of impacts needed: number of impacts = total energy / (E × 0.65).

Let's calculate the solution.

Solution

Step 1: Calculate the gravitational potential energy of the steam hammer: potential energy = 17,200 kg × 9.8 N/kg × 3.6 m.

The potential energy of the steam hammer is 6,365,760 J.

Step 2: Calculate the energy transferred to the lead slug during each impact: energy transferred = E × 0.65.

Step 3: Calculate the total energy required to raise the temperature of the lead slug by 46°C: total energy = 221 kg × 250 J/(kg·°C) × 46°C.

The total energy required is 2,557,500 J.

Step 4: Calculate the number of impacts needed: number of impacts = total energy / (E × 0.65).

Now, we need to solve the equation 2,557,500 J = (E × 0.65) × number of impacts to find the value of the number of impacts.

Unfortunately, the value of the energy transferred per impact (E) is not provided in the given information. Without this value, we cannot calculate the number of impacts needed.

Please provide the value of the energy transferred per impact (E) so that we can proceed with the calculation.