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
VashaNatasha [74]
3 years ago
11

Peter was holding a Human Physiology textbook that weighs about 4lbs with his non- writing arm for one minute. His elbow remaine

d exactly at a 45° isometric position. He did not complain of any muscle fatigue or muscle weakness. a) i. Is the number of activated motor units stay the same while he was holding the book for two minutes? (0.5 pt) ii. Why? (0.5 pt) Increasing the period Peter is holding the texting will only cause the motor units to fire more frequently to keep the muscles from relaxing. b) i. Are the same motor units activated while he was holding the book for two minutes? (0.5 pt) ii. Why? (0.5 pt)
Physics
1 answer:
Slav-nsk [51]3 years ago
4 0

Answer:

a

When peter held the book for one minute the rate at which motor unites are fired increase steeply but as the duration increases the increese in the rate at which it is being fired becomes linear so the number of activated motors stay the same but are being activated at a more rapidly

b

The same motors are activated whilest he is hold the book for 2 minutes this is because for peter to hold the book in one fixed position one specific motor units  need to be activated

Note changing the motor unites would change the positon of the hand

Explanation:

You might be interested in
Refer to the first diagram. What is the weight of the person hanging on the end of the seesaw in Newtons?
irina1246 [14]

Due to equilibrium of moments:

1) The weight of the person hanging on the left is 250 N

2) The 400 N person is 3 m from the fulcrum

3) The weight of the board is 200 N

Explanation:

1)

To solve the problem, we use the principle of equilibrium of moments.

In fact, for the seesaw to be in equilibrium, the total clockwise moment must be equal to the total anticlockwise moment.

The moment of a force is defined as:

M=Fd

where

F is the magnitude of the force

d is the perpendicular distance of the force from the fulcrum

In the first diagram:

- The clockwise moment is due to the person on the right is

M_c = W_2 d_2

where W_2 = 500 N is the weight of the person and d_2 = 2 m is its distance from the fulcrum

- The anticlockwise moment due to the person hanging on the left is

M_a = W_1 d_1

where W_1 is his weight and d_1 = 4 m is the distance from the fulcrum

Since the seesaw is in equilibrium,

M_c = M_a

So we can find the weight of the person on the left:

W_1 d_1 = W_2 d_2\\W_1 = \frac{W_2 d_2}{d_1}=\frac{(500)(2)}{4}=250 N

2)

Again, for the seesaw to be in equilibrium, the total clockwise moment must be equal to the total anticlockwise moment.

- The clockwise moment due to the person on the right is

M_c = W_2 d_2

where W_2 = 400 N is the weight of the person and d_2 is its distance from the fulcrum

- The anticlockwise moment due to the person on the left is

M_a = W_1 d_1

where W_1 = 300 N is his weight and d_1 = 4 m is the distance from the fulcrum.

Since the seesaw is in equilibrium,

M_c = M_a

So we can find the distance of the person on the right:

W_1 d_1 = W_2 d_2\\d_2 = \frac{W_1 d_1}{W_2}=\frac{(300)(4)}{400}=3 m

3)

As before, for the seesaw to be in equilibrium, the total clockwise moment must be equal to the total anticlockwise moment.

- The clockwise moment around the fulcrum this time is due to the weight of the seesaw:

M_c = W_2 d_2

where W_2 is the weight of the seesaw and d_2 = 3 m is the distance of its centre of mass from the fulcrum

- The anticlockwise moment due to the person on the left is

M_a = W_1 d_1

where W_1 = 600 N is his weight and d_1 = 1 m is the distance from the fulcrum

Since the seesaw is in equilibrium,

M_c = M_a

So we can find the weight of the seesaw:

W_1 d_1 = W_2 d_2\\W_2 =\frac{W_1 d_1}{d_2}= \frac{(600)(1)}{3}=200 N

#LearnwithBrainly

8 0
3 years ago
Lillie is running. She increases her initial speed of 30 km/h to 40 km/h so she can win the race. If she takes 0.05 hours to com
Ganezh [65]

Explanation:

First convert the speed into m/s and time into seconds

5 0
2 years ago
Newtons first law stateS that object will move With a constant velocity if nothing acts on it. Does our every day experience con
bazaltina [42]

Answer:

hi

Explanation:

hi

4 0
2 years ago
Identify two potential improvements to the opal extraction process and explain how these improvements could minimize harm to the
Orlov [11]

Answer

• Improving the environmental performances

• Developing Green Mining technology

Explanation

The effect to the environment caused by opal mining are; impact on soils and geology, clearing of native vegetation disrupting flora and fauna, change in land use and effects of air quality.

Opal mining is currently examining environmental impacts and adopting measures that mitigate the impacts making the process less destructive to the environment.

With the current commitment to sustainability, opal companies are investing funds for Green Mining as a positive way to impact the environment before and after mining.


7 0
3 years ago
Read 2 more answers
****PLEASE HELP**** WILL MARK BRAINLIEST
allochka39001 [22]

Answer:

The Current decreases

Explanation:

HOPE THIS HELPS!

4 0
2 years ago
Other questions:
  • Alex climbs to the top of a tall tree while his friend Gary waits on the ground below. Alex throws down a ball at 8 m/s from 50
    5·1 answer
  • The speed of sound I gases depends on <br> a humidity <br> b air<br> c temperature <br> d visibility
    15·1 answer
  • I NEED HELP ON PHYSICAL SCIENCE; WORK
    7·2 answers
  • An astronaut of mass m in a spacecraft experiences a gravitational force F=mg when stationary on the launchpad.
    15·1 answer
  • What force (in N) does a trampoline have to apply to a 46.0 kg gymnast to accelerate her straight up at 5.30 m/s2? Note that the
    9·2 answers
  • What would a physicist do to determine how tires affect the motion of a car?
    15·1 answer
  • A Plane crashes into the side of a mountain. If the crash took place over 9
    7·1 answer
  • Two alternate exterior angles are formed by a transversal through two parallel lines. If one of these alternate exterior angles
    5·1 answer
  • A cart is pushed on a frictionless floor with 29.6 Newtons of force along a distance of 5.9 meters in 8.1 seconds. How much powe
    14·1 answer
  • The length of a soild of a metallic cube at 20°C is 5•0cm. Given that the linear expansivity of the metal is 4×^-5k^-1. Find the
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!