Question

Мальчик массой 45 кг стоит на лыжах. Длина каждой лыжи 1,5,ширина 10 см. Какое давление оказывает мальчик на снег? Сравните его с давлением, которое производит мальчик, стоящий без лыж.

Answer 1

Дано
Рм=15кПа
m=45kг
l=1,5м           ! решение
d=0,1м          ! p= F/S  !  S=1,5*0,1=0,15м2
                       !              !   Р=10Н/кг*45кг=450Н
q=10Н/кг       ! F=P      !   р=450Н/0,15м2=3000Па
________     ! P=qm   !   Рм/р=15000Па/3000Па=5 раз
Р=?               ! S=1*d    !  Ответ: в 5 раз.
Рм/р-?          !

Answer 2

Calculation of Pressure

To calculate the pressure exerted by the boy on the snow while standing on skis, we need to use the formula:

Pressure = Force / Area

In this case, the force exerted by the boy is equal to his weight, and the area is the contact area between the skis and the snow.

Given: - Mass of the boy = 45 kg - Length of each ski = 1.5 m - Width of each ski = 10 cm = 0.1 m

To calculate the contact area, we need to multiply the length and width of one ski:

Area = Length x Width

Area = 1.5 m x 0.1 m

Now, let's calculate the pressure exerted by the boy on the snow:

Pressure = Weight / Area

To calculate the weight, we can use the formula:

Weight = Mass x Gravity

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

Let's plug in the values and calculate the pressure:

Weight = 45 kg x 9.8 m/s^2

Area = 1.5 m x 0.1 m

Pressure = (45 kg x 9.8 m/s^2) / (1.5 m x 0.1 m)

Calculating this expression gives us the pressure exerted by the boy on the snow.

Comparison with Standing Without Skis

To compare the pressure exerted by the boy while standing on skis with the pressure exerted while standing without skis, we need to consider the contact area in both cases.

When standing without skis, the contact area is determined by the size of the boy's feet. However, since the question does not provide information about the size of the boy's feet, we cannot accurately calculate the contact area in this case.

Therefore, we can only compare the pressure exerted by the boy on the snow while standing on skis with the pressure exerted by the same boy on the snow while standing without skis if we assume that the contact area is the same in both cases.

If we assume that the contact area is the same, we can compare the pressures calculated above to determine the difference.

Please note that the actual pressure exerted by the boy while standing without skis may vary depending on the size of his feet and the distribution of his weight.