Physics, 17.11.2019 05:31 poohnia

A1.0 kg block is pushed 2.0 m at a constant velocity up a vertical wall by a constant force applied at an angle of 29.0 ◦ with the horizontal, as shown in the figure. the acceleration of gravity is 9.81 m/s 2 . if the coefficient of kinetic friction between the block and the wall is 0.20, find a) the work done by the force on the block. answer in units of j. b) the work done by gravity on the block. c) the magnitude of the normal force between the block and the wall. answer in units of n

Answers: 1

Show answers

Answers

Answer from: juansebas35

a) 35.08 J

b) -19.62 J

c) 17.53 N

Explanation:

A figure is attached in order to understand better the question. In addition, we have the following data:

m=1 kg is the mass of the block

d=2 m is the distance the block is pushed at constant velocity

$\theta=29\°$ is the angle at wich the force is applied

$g=9.81 m/s[^{2}$ is the acceleration due gravity

$\mu_{k}=0.2$ is the coefficient of kinetic friction between the block and the wall

Now, if we draw a free body diagram of this situation we will have the following:

$\sum{F_{netx}}=-N+F_{x}=0$

Where is the Normal force and $F_{x}=Fcos(29\°)$ is the horizontal component of the applied force

Then: $N=Fcos(29\°)$ (1)

$\sum{F_{nety}}=F_{y}-F_{friction}-Fg=0$

Where $F_{y}=Fsin(29\°)$ is the vertical component of the applied force , $F_{friction}=\mu_{k}N=\mu_{k}Fcos(29\°)$ is the Friction force and Fg=mg is the force due gravity (the weight of the block)

Then: $Fsin(29\°)-\mu_{k}Fcos(29\°)-mg=0$ (2)

Finding from (2):

$F=\frac{mg}{sin(29\°)-\mu_{k}cos(29\°)}$ (3)

$F=\frac{(1 kg)(9.81 m/s^{2})}{sin(29\°)-0.2cos(29\°)}$ (4)

F=20.05 N (5)

a) Now we can calculate the work done by the force

When the applied force and the direction of motion form an angle the expression to calculate the Work is:

$W=Fdcos{\theta}$ (6)

$W=(20.05 N)(2 m)cos{29\°}$ (7)

W=35.08 J (8) This is the work done by

b) The work done by gravity on the block

In this case the work equation is:

$Wg=Fg d cos{\alpha}$ (9)

Where:

$Fg=mg=(1 kg)(9.81 m/s^{2})=9.81 N$ is the gravity force on the block

$\alpha=180\°$ is the angle between the gravity force and the direction of motion

$Wg=(9.81 N)(2 m) cos(180\°)$ (10)

Wg=-19.62 J (11) Note the work is negative because the applied force is in the opposite direction of motion

c) The magnitude of the normal force

From (1) we know the Normal force is:

$N=Fcos(29\°)$ (1)

Since F=20.05 N , we have:

$N=20.05 N cos(29\°)$ (12)

N=17.53 N (13) This is the Normal force

A1.0 kg block is pushed 2.0 m at a constant velocity up a vertical wall by a constant force applied

Answer from: Quest

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

Answer from: Quest

radial fractures in a piece of glass look most like which of the following?

a. spokes of a wheel

b. a circle

c. a zig zag

d. none of the above

the correct answer is a. spokes of a wheel

hope this (:

Another question on Physics

Physics, 21.06.2019 18:00

What is the magnification of a real image if the image is 10.0 cm from a mirror and the object is 50.0 cm from the mirror ? use the equation m=-di/do. a. -5.0 b. 5.0 c. 0.20 d. -0.20

Answers: 1

Answer

Physics, 22.06.2019 09:30

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

Answers: 3

Answer

Physics, 22.06.2019 12:30

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

Answers: 3

Answer

Physics, 22.06.2019 13:40

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these

Answers: 1

Answer

You know the right answer?

A1.0 kg block is pushed 2.0 m at a constant velocity up a vertical wall by a constant force applied...

Questions