Question

Длина наклонной доски 6 м. Один конец имеет высоту 2 м, а другой находится на земле. Ящик весом 80 кг ставится на самый верх доски. Какова минимальная сила, приложенная параллельно доске для удержания ящика на месте, если силой трения можно пренебречь4? Вычислите ускорение ящика, если его отпустить и силой трения можно пренебречь. Чему равна сила трения, если ящик скользит по доске? * Чему равен коэффициент трения в этом случае?

Answer 1

Ответ:

Aп=m*g*h=40*10*2=800 Дж

Аз=Aп+Fтр*S=800+25*6=950

Ап*100.Аз=800*100/950=84 %

Answer 2

Given Information:

- Length of the inclined board: 6 m - Height of one end of the board: 2 m - Weight of the box: 80 kg - Force of friction can be neglected

Minimum Force to Hold the Box in Place:

To find the minimum force required to hold the box in place, we need to consider the forces acting on the box. The box experiences two forces: the force of gravity and the force applied parallel to the board to hold the box in place.

The force of gravity acting on the box can be calculated using the formula:

Force of gravity = mass × acceleration due to gravity

The acceleration due to gravity is approximately 9.8 m/s^2.

Force of gravity = 80 kg × 9.8 m/s^2

To hold the box in place, the force applied parallel to the board must be equal to the force of gravity. Therefore, the minimum force required to hold the box in place is:

Minimum force = Force of gravity

Acceleration of the Box:

If the box is released and the force of friction can be neglected, the box will accelerate down the inclined board due to the force of gravity. The acceleration of the box can be calculated using the formula:

Acceleration = (Force of gravity - Force of friction) / mass

Since the force of friction can be neglected, the acceleration of the box is:

Acceleration = Force of gravity / mass

Force of Friction:

If the box is sliding down the inclined board, the force of friction will act in the opposite direction to the motion of the box. However, in this case, the force of friction can be neglected.

Coefficient of Friction:

Since the force of friction can be neglected, the coefficient of friction is not applicable in this case.

Let's calculate the values using the given information:

Force of gravity = 80 kg × 9.8 m/s^2

Acceleration = Force of gravity / mass

Please note that the exact values cannot be determined without the specific values for the force of gravity and the mass of the box. However, you can use the given information to calculate the values using the formulas provided above.