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
levacccp [35]
3 years ago
7

A man weighing 180 lbf pushes a block weighing 100 lbf along a horizontal plane. the dynamic coefficient of friction between the

block and plane is 0.2. assuming that the block moves at a constant speed, how much work is required to move the block 100 ft considering the (a) the block and (b) the man as the system.
Physics
1 answer:
Talja [164]3 years ago
3 0
The first thing you should know is that the work is defined as:
 W = F * d
 Where
 F = force
 d = displacement
 We have then
 (a) the block
 F = (0.2) * (100) = 20
 d = 100
 W = (20) * (100) = 2000 ft.lbf
 (b) the man as the system.
 F = (0.2) * (100 + 180) = 56
 d = 100
 W = (56) * (100) = 5600 ft.lbf
 answer:
 (a) 2000 ft.lbf
 (b) 5600 ft.lbf
You might be interested in
Reasons why inductors opposes charges passing through it<br>​
saul85 [17]

Answer:

é isso daí msm

Explanation:

oq eu falei

8 0
2 years ago
NEED HELP PLEASE !!!!!!!!!!!!!!!!!!!!!!!!!!
Anna [14]

Answer:

(1) Exercise should be painful in order for it to be beneficial. FALSE

(2) Proper progression involves a gradual increase in the level of exercise. TRUE

(3) Exercising on a regular, consistent basis provides you with the best results. TRUE

Explanation:

(1) It is a false statement because whenever we do exercise, it should not be painful, it should be comfortable to some extent for a person, if it will be painful then it means one cant get the true and genuine benefit from the exercise.

(2) It is very much true because one must keep on increasing the level of his/her exercise gradually with the passage of time, it will make his/her body synchronized with the exercise properly.

(3) It is also a true statement because, one must use variety of exercises in his/her workout session targeting different muscles and different areas and parts of the body to make exercise really beneficial.

3 0
3 years ago
Frame S' passes frame S in the usual way. Two events are simultaneous in S'.
yuradex [85]

Answer:

c)They can also be simultaneous in S if their separation is zero.

Explanation:

By relativity theory, we can say two events when seen from two different reference frames can only be simultaneous when they are at the same space location and occur simultaneously in at least one reference frame, therefore when Frame S′ usually passes Frame S. Two occurrences in S′ are simultaneous, therefore these occurrences can be simultaneous in S when their separation is 0 (that is they are at the same location)

And therefore option c. If their separation is zero, they can also be simultaneous in S.

8 0
3 years ago
Express in words AND mathematically the relationship between…<br> Period and frequency
castortr0y [4]
Frequency = how many waves you get per sec
Period = how long each wave takes

Period = 1/frequency
6 0
3 years ago
A block is at rest on a plank whose angle can be varied. The angle is gradually increased from 0 deg. At 31.8°, the block starts
galina1969 [7]

Answer:

\mu_s = 0.62

\mu_k = 0.415

The motion of the block is downwards with acceleration 1.7 m/s^2.

Explanation:

First, we will calculate the acceleration using the kinematics equations. We will denote the direction along the incline as x-direction.

x - x_0 = v_0t + \frac{1}{2}at^2\\3.4 = 0 + \frac{1}{2}a(2)^2\\a = 1.7~m/s^2

Newton’s Second Law can be used to find the net force applied on the block in the -x-direction.

F = ma\\F = 1.7m

Now, let’s investigate the free-body diagram of the block.

Along the x-direction, there are two forces: The x-component of the block’s weight and the kinetic friction force. Therefore,

F = mg\sin(\theta) - \mu_k mg\cos(\theta)\\1.7m = mg\sin(31.8) - \mu_k mg\cos(31.8)\\1.7 = (9.8)\sin(\theta) - mu_k(9.8)\cos(\theta)\\mu_k = 0.415

As for the static friction, we will consider the angle 31.8, but just before the block starts the move.

mg\sin(31.8) = \mu_s mg\cos(31.8)\\\mu_s = tan(31.8) = 0.62

5 0
3 years ago
Other questions:
  • Car has a mass of 710 kg. it starts from rest and tevels 40.0 m in 3.0 s. the car is uniformly accelarting. what is the net forc
    6·1 answer
  • Calculated the gravitational potential energy of a 93.0 kg sky diver who is 550 m above the ground
    5·1 answer
  • Which statement best compares momentum and kinetic energy?
    9·2 answers
  • A circuit consists of a series combination of 5.50 âkΩ and 5.00 âkΩ resistors connected across a 50.0-V battery having negligi
    7·1 answer
  • Scouts at a camp shake the rope bridge they have just crossed and observe the wave crests to be 9.70 m apart. If they shake the
    9·1 answer
  • Which statement about subatomic particles is NOT true?
    5·1 answer
  • Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. After chatting for a few min
    15·1 answer
  • Which one is it? Chemical, or ,Mechanical<br><br><br> Flakes of brick fall off due to wind and rain.
    5·2 answers
  • If the acceleration of an object increases, what effect does this have on the Force and Mass?
    11·2 answers
  • Say you were at mission control on
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!