When did the object have the highest average

As a child walks, for a brief moment his entire weight is placed on one heel, which can be approximated as a small circle. Calcu

Brut [27]

The correct answer is option b, 63.6 kPa

Given,

The diameter of the heel, d=7 cm=0.07 m

The mass of the child, m=25 kg

The pressure is given by the ratio of the force to the area through which the force is applied.

The force applied on the floor by the child is equal to its weight.

Thus the pressure applied on the floor by the child is given by,

$\begin{gathered} P=\frac{F}{A} \\ =\frac{mg}{\pi(\frac{d}{2})^2} \end{gathered}$

Where A is the area of the cross-section of the heel.

On substituting the known values,

$\begin{gathered} P=\frac{25\times9.8}{\pi(\frac{0.07}{2})^2} \\ =63.6\times10^3\text{ Pa} \\ =63.6\text{ kPa} \end{gathered}$

Thus the pressure applied on the floor by the heel is 63.6 kPa

4 0

1 year ago

A solid object has a density of 2.85 g/cm3. According to Archimedes, what can be done to make this object float in water?

Juli2301 [7.4K]

2: It's not just the capillary action, but the pull from transpiration (the evaporation of water from the tree) that is used to pull water up from the roots.

The second question needs context. Strong bonds alone won't cause tension. I don't see how adhesion is different. High vapour pressure could do it, but it's the difference in pressures that'd cause tension (and the resistance of that pressure by the surface). So, a low and high pressure would be needed. Poorly worded question :( 

1: "Adhesion is the tendency of certain dissimilar molecules to cling together due to attractive forces." [1] 

3: The other three answere would not work. Think of a boat. 

3: If you push gas, it will be compressed(get smaller). If you push liquid it will push something else. Thus, liquids are good for transferring force. This is a hydraulic system.

4 0

3 years ago

Suppose two children push horizontally, but in exactly opposite directions, on a third child in a sled. The first child exerts a

anyanavicka [17]

Answer:

Please, read the anser below

Explanation:

1. In order to calculate the acceleration of the children you use the Newton second law for the summation of the implied forces:

$F_2-F_1-F_f=Ma$ (1)

Where is has been used that the motion is in the direction of the applied force by the second child

F2: force of the second child = 92N

F1: force of the first child = 79N

Ff: friction force = 5.5N

M: mass of the third child = 24kg

a: acceleration of the third child = ?

You solve the equation (1) for a, and you replace the values of the other parameters:

$a=\frac{F_2-F_1.F_f}{M}=\frac{96N-79N-5.5N}{24kg}=0.48\frac{m}{s^2}$

The acceleration is 0.48m/s^2

2. The system of interest is the same as before, the acceleration calculated is about the motion of the third child.

3. An image with the diagram forces is attached below.

4. If the friction would be 150N, the acceleration would be zero, because the friction force is higher than the higher force between children, which is 92N.

Then, the acceleration is zero