Question

ПОМОГИТЕ ПОЖАЛУЙСТА! Человек массой 60 кг начинает движение из состояния покоя, и через 4 с его скорость становится равной 10 м/с. Чему равна его полезная мощность?

Answer 1

Дано  m=60 кг   V=10 м/с    t=4 с

A=m*V^2/2=60*100/2=3000 Дж

P=A/t=3000/4=750 Вт

Ответ P=750 Вт

Answer 2

P = $\frac{A}{t}$

A - работа 
t - время ( 4 с )

A = F * S 

F - сила 
S - путь 

F = m * g 

m - масса ( 60 кг )
g - ускорение свободного падения ( 10 Н / кг )

F = 60 * 10 = 600 H 

S = $\frac{a * t^2}{2}$

a - ускорение 
t - время ( 4 с = 4² = 16 с )

a = $\frac{V - V_{0} }{t}$

V - конечная скорость ( 10 м / c )
Vo - начальная скорость ( 0 м / c )
t = 4 c 

a = $\frac{10 - 0}{4}$ = 2,5 м / c²

S = $\frac{2,5 * 16}{2}$ = 20 м 

A = F * S = 600 * 20 = 12000 Дж 

P = $\frac{12000}{4}$ = 3000 Вт = 3 кВт 

Answer 3

Calculation of Useful Power

To calculate the useful power, we need to determine the work done by the person and the time it takes to do that work. The formula for power is:

Power = Work / Time

To find the work done by the person, we can use the formula:

Work = Force × Distance

In this case, the force can be calculated using Newton's second law of motion:

Force = Mass × Acceleration

Given that the mass of the person is 60 kg and the acceleration can be calculated using the formula:

Acceleration = Change in velocity / Time

The change in velocity can be calculated by subtracting the initial velocity from the final velocity:

Change in velocity = Final velocity - Initial velocity

Given that the initial velocity is 0 m/s and the final velocity is 10 m/s, we can calculate the change in velocity.

Finally, we can substitute the values into the formulas to calculate the useful power.

Let's calculate the values step by step.

Calculation Steps:

1. Calculate the change in velocity: - Initial velocity = 0 m/s - Final velocity = 10 m/s - Change in velocity = Final velocity - Initial velocity

2. Calculate the acceleration: - Time = 4 s - Acceleration = Change in velocity / Time

3. Calculate the force: - Mass = 60 kg - Force = Mass × Acceleration

4. Calculate the work done: - Distance = ? - Work = Force × Distance

5. Calculate the useful power: - Time = 4 s - Power = Work / Time

Let's calculate the values.

Calculation:

1. Change in velocity: - Initial velocity = 0 m/s - Final velocity = 10 m/s - Change in velocity = Final velocity - Initial velocity = 10 m/s - 0 m/s = 10 m/s

2. Acceleration: - Time = 4 s - Acceleration = Change in velocity / Time = 10 m/s / 4 s = 2.5 m/s²

3. Force: - Mass = 60 kg - Force = Mass × Acceleration = 60 kg × 2.5 m/s² = 150 N

4. Work done: - Distance = ? - Work = Force × Distance

5. Useful power: - Time = 4 s - Power = Work / Time

Unfortunately, we are missing the distance traveled by the person. Without knowing the distance, we cannot calculate the work done or the useful power. Please provide the distance traveled, and we will be able to assist you further.