Question

Тело массой 20 кг тянут с силой 120Н по горизонтальной поверхности,если эта сила приложена под 60 градусами к горизонту,то тело движется равномерно. С каким ускорением будет двигаться тело,если эту же силу приложить под углом в 30 градусов

Answer 1

M= 20 кг
F=120H
угол A=60
угол A1=30
a-?

Сила F направлена под углом 60 градусов.
Проекция силы F на поверхности Fx=F*cosA
Сила сопротивления Fc=mg-F*sinA
Движение равномерное Fx=Fc
F*cosA=mg-F*sinA
Сила F направлена под углом 30
Проекция F на горизонтальную поверхность Fx=F*cosA1
Сила сопротивления движению Fc=mg-F*sinA1
равнодействующая сила R=Fx-Fc=ma
следовательно ускорение a=(Fx-Fc)/m=(F*cosA1-mg-F*sinA1)/m=(F*cosA1-(F*cosA/(mg-F*sinA))(mg-F*sinA1))/m=(120*cos30-(120*cos60/(20*10-120*sin60))(20*10*sin30))/20=0.8246=0.8 м/с^2

Ответ 0,8 м/с^2

Answer 2

Calculation of Acceleration

To calculate the acceleration of the body, we need to use Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

The formula for acceleration is:

a = F / m

Where: - a is the acceleration - F is the net force acting on the object - m is the mass of the object

In the given scenario, the mass of the body is 20 kg and the force applied is 120 N at an angle of 60 degrees to the horizontal.

Using the given force and mass, we can calculate the acceleration:

a = 120 N / 20 kg = 6 m/s^2 Therefore, the body will move with an acceleration of 6 m/s^2.

Calculation of Acceleration at a Different Angle

Now, let's calculate the acceleration when the same force of 120 N is applied at an angle of 30 degrees to the horizontal.

Using the same formula as before, we can calculate the new acceleration:

a = F / m

Where: - a is the acceleration - F is the net force acting on the object - m is the mass of the object

Using the given force and mass, we can calculate the new acceleration:

a = 120 N / 20 kg = 6 m/s^2 Therefore, the body will still move with an acceleration of 6 m/s^2 when the force is applied at an angle of 30 degrees to the horizontal.

Conclusion

In both cases, when the force is applied at an angle of 60 degrees and 30 degrees to the horizontal, the body will move with the same acceleration of 6 m/s^2.

Please note that the calculations assume ideal conditions and do not take into account factors such as friction or air resistance.