1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lisabon 2012 [21]
3 years ago
5

Very large forces are produced in joints when a person jumps from some height to the ground. Calculate the force produced if an

79.0–kg person jumps from a 0.510–m-high ledge and lands stiffly, compressing joint material 1.30 cm as a result. (Be certain to include the weight of the person.) 3.04*10^4J Incorrect. Tries 1/7 Previous Tries In practice the knees bend almost involuntarily to help extend the distance over which you stop. Calculate the force produced if the stopping distance is 0.345 m. 1.92×103 J You are correct. Find the ratio of the force in part (a) with the weight of the person. Tries 0/7 Find the ratio of the force in part (b) with the weight of the person.
Physics
1 answer:
krok68 [10]3 years ago
4 0

Answer:

A) 31 kJ

B)  1.92 KJ

C) 40 ,  2.48

Explanation:

weight of person ( m ) = 79 kg

height of jump ( h ) = 0.510 m

Compression of joint material ( d ) = 1.30 cm ≈  0.013 m

A) calculate the force

Fd = mgh

F = mgh / d

W = mg

F(net) = W + F  = mg ( 1 + \frac{h}{d} )

          =  79 * 9.81 ( 1 + (0.51 / 0.013) )

          = 774.99 ( 40.231 ) ≈ 31 KJ

B) calculate the force when the stopping distance = 0.345 m

d = 0.345 m

Fd = mgh  hence  F = mgh / d

F(net) = W + F  = mg ( 1 + \frac{h}{d} )

          =  79 * 9.81 ( 1 + (0.51 / 0.345) )

          = 774.99 ( 2.478 ) = 1.92 KJ

C) Ratio of force in part a with weight of person

=  31000 / ( 79 * 9.81 ) = 31000 / 774.99 = 40

  Ratio of force in part b with weight of person

= 1920 / 774.99 = 2.48

You might be interested in
Which receptors are responsible for the production of saliva (A) auditory receptors (B) optic receptors (C) skin receptors (D) t
Fudgin [204]

Answer:

\large \boxed{\sf D. \ taste \ receptors}

Explanation:

When activated, the receptor most likely prompting the production of saliva is the taste receptor. When food enters the mouth, the salivary glands produce the saliva upon the sensation of taste.

8 0
2 years ago
A device that uses electricity and magnetism to create motion is called a
Lady bird [3.3K]

Answer:

electric motors is the answer

8 0
2 years ago
Read 2 more answers
In which situation is static electricity most likely to form?
Papessa [141]

Answer:

I'd go for 'Marie drives a car'

Explanation:

Static electricity will possible form in all the scenarios, but is more likely to form when you're driving a car. This is due to the friction between the body of the car and the particles in the air around the body of the car. This is why chains are sometimes attached to fuel tankers when transporting them. The chain is made to touch the ground so that any charge built up can be safely conducted to the earth, reducing the chances of a fire outbreak due to charges igniting the fuel.

7 0
3 years ago
Read 2 more answers
reviews the approach taken in problems such as this one. A bird watcher meanders through the woods, walking 0.916 km due east, 0
Verizon [17]

Answer:

Displacement: 2.230 km    Average velocity: 1.274\frac{km}{h}

Explanation:

Let's represent displacement by the letter S and the displacement in direction 49.7° as A. Displaement is a vector, so we need to decompose all the bird's displacement into their X-Y compoments. Let's go one by one:

  • 0.916 km due east is an horizontal direction and cane be seen as  direction towards the negative side of X-axis.
  • 0.928 km due south is a vertical direction and can be seen as a direction towards the negative side of Y-axis.
  • 3.52 km in a direction of 49.7° has components on X and Y  axes. It is necessary to break it down using trigonometry,

First of all. We need to sum all the X components and all the Y componets.

∑Sx = Ax -0.916 ⇒  ∑Sx = [tex]3.52cos(49.7) - 0.916

∑Sx = 1.361 km

∑Sy = Ay - 0.918 ⇒ ∑Sy = 3.52sin(49.7) - 0.918

∑Sy = 1.767

The total displacement is calculated using Pythagoeran therorem:

S_{total} =\sqrt{Sx^{2}+ Sy^{2} } ⇒

S_{total} = 2.230 km

With displacement calculated, we can find the average speed as follows:

V = S/t  ⇒  V = \frac{2.230}{1.750}

V = 1.274\frac{km}{h}

7 0
3 years ago
The moment of inertia of a thin uniform rod of mass M and length L about an Axis perpendicular to the rod through its Centre is
sleet_krkn [62]

Answer:

I = I₀ + M(L/2)²

Explanation:

Given that the moment of inertia of a thin uniform rod of mass M and length L about an Axis perpendicular to the rod through its Centre is I₀.

The parallel axis theorem for moment of inertia states that the moment of inertia of a body about an axis passing through the centre of mass is equal to the sum of the moment of inertia of the body about an axis passing through the centre of mass and the product of mass and the square of the distance between the two axes.

The moment of inertia of the body about an axis passing through the centre of mass is given to be I₀

The distance between the two axes is L/2 (total length of the rod divided by 2

From the parallel axis theorem we have

I = I₀ + M(L/2)²

5 0
3 years ago
Other questions:
  • Minerals must be _____.
    8·2 answers
  • what is the resistance of a 12m long wire having radius( 2*10 to the power - 4) and resistivity (3.14*10 to the power - 8)ohmM
    7·1 answer
  • The destruction of the ozone layer primarily occurs in the mesosphere. thermosphere. stratosphere. troposphere.
    13·2 answers
  • An astronaut in a spacecraft looks out her window and observes a comet travel in the opposite direction at a relative speed of 2
    8·2 answers
  • A 20.0 μF capacitor initially charged to 30.0 μC is discharged through a 1.20 kΩ resistor. How long does it take to reduce the c
    13·1 answer
  • If 1.3 grams of air has a volume of 1000cm ^3, what is the density of air?
    13·2 answers
  • A bicycle travels 10 km in 20 minutes. What is its average speed (in km/h) ?
    13·1 answer
  • A place where two plates slip past each other, moving in opposite directions, is known as a
    10·2 answers
  • 4.
    6·1 answer
  • Consider the following hypothetical subject performing the EMG laboratory: Immediately after the subject's maximum grip strength
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!