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
bulgar [2K]
4 years ago
10

A box of mass 3.1kg slides down a rough vertical wall. The gravitational force on the box is 30N . When the box reaches a speed

of 2.5m/s , you start pushing on one edge of the box at a 45? angle (use degrees in your calculations throughout this problem) with a constant force of magnitude Fp = 23N , as shown in figure. (Figure 1) There is now a frictional force between the box and the wall of magnitude 13N . How fast is the box sliding 2.0s after you started pushing on it?
Using our simplified model, in which we know that the forces are constant (but we don't know what their magnitudes are), which of the following motion diagrams would be a reasonable representation of the motion of the box?
Physics
2 answers:
hoa [83]4 years ago
6 0

Answer:

The speed of the box after 2 s is 3 m/s.

Explanation:

The net force on the box in vertical direction:

{F_{net}} = {F_g} - f - {F_p}\sin {45^{\rm{o}}}F

Here, {F_g} is the gravitational force, f is the force of friction and {F_p} is the pushing force.

According to Newton’s second law, the net force is:

{F_{net}} = ma

Here, a is the acceleration in vertical direction

\begin{array}{c}\\ \Rightarrow ma = {F_g} - f - {F_p}\sin {45^{\rm{o}}}\\\\a = \frac{{{F_g} - f - {F_p}\sin {{45}^{\rm{o}}}}}{m}\\\end{array}

Substitute 30N for Fg, 13N for f and 23N for Fp

 \begin{array}{c}\\a = \frac{{\left( {30{\rm{ N}}} \right) - \left( {13{\rm{ N}}} \right) - \left( {23{\rm{ N}}} \right)\sin {{45}^{\rm{o}}}}}{{3.1{\rm{ kg}}}}\\\\ = \frac{{0.7365{\rm{ N}}}}{{3.1{\rm{ kg}}}}\\\\ = 0.24\;{\rm{m/}}{{\rm{s}}^{\rm{2}}}\\\end{array}

Newton’s equation of motion:

v - u = at

Substitute 2.5m/s for u , 0.24m/s2 for a and 2s for t .

\begin{array}{c}\\v - 2.5{\rm{ m/s}} = \left( {0.24{\rm{ m/}}{{\rm{s}}^2}} \right)\left( {2{\rm{ s}}} \right)\\\\v = 0.48{\rm{ m/s}} + 2.5{\rm{ m/s}}\\\\ = 2.98{\rm{ m/s}}\\\\ \approx {\bf{3 m}}{\rm{/}}{\bf{s}}\\\end{array}

The speed of the box after 2 s is 3 m/s.

Tems11 [23]4 years ago
5 0

Answer:

The box will be moving at 0.45m/s. The solution to this problem requires the knowledge and application of newtons second law of motion and the knowledge of linear motion. The vertical component of the force Fp acts vertically upwards against the directio of motion. This causes a constant upward force of 23sin45° to act on the box. Fhe frictional force of 13N also acts vertically upwards and so two forces act upwards against rhe force of gravity resulting un a net force of 0.7N acting kn the box. This corresponds to an acceleration of 0.225m/s². So in w.0s after i start to push v = 0.45m/s.

Explanation:

You might be interested in
What does the speed of sound depend on?
melamori03 [73]
Assuming it's an ideal material, the answer is A.

The speed of sound depends on the medium that the sound travels through.
5 0
3 years ago
Read 2 more answers
If the frequency of q of a trait is 0.4, what is the frequency of p?
lianna [129]
In genetic traits, p and q represent the relative probabilities of the two alleles manifesting. If these two are the only options (ex. a dominant one and a recessive one), then the probabilities of both must sum up to 1. In this case, since we are given that q = 0.4, then p + q = 1, p + 0.4 = 1, and p = 0.6.
4 0
3 years ago
Read 2 more answers
Describe 2 ways you could increase the efficiency of a household central heating system
chubhunter [2.5K]

Answer:

Arrange an annual service. Treat your boiler like your car. ...

Keep your boiler clean. ...

Bleed your radiators. ...

Top up the pressure. ...

Use a Powerflush. ...

Insulate your pipes. ...

Turn the heating on. ...

If all else fails…

Explanation:

6 0
3 years ago
Net force is the sum of all forces acting on an object. For example, in a tug of war, when one team is pulling the rope with a f
melisa1 [442]

Answer:

If there are equal forces in both directions and there is no motion, the net force is 0 Newtons. This is because you'd be subtracting 100 from 100 which just equals 0.

5 0
3 years ago
Two metal disks, one with radius R1 = 2.45 cm and mass M1 = 0.900 kg and the other with radius R2 = 5.00 cm and mass M2 = 1.60 k
natima [27]

Answer:

part (a) a_1\ =\ 2.9\ kg

Part (b) a_2\ =\ 6.25\ kg

Explanation:

Given,

  • mass of the smaller disk = M_1\ =\ 0.900\ kg
  • Radius of the smaller disk = R_1\ =\ 2.45\ cm\ =\ 0.0245\ m
  • mass of the larger disk = M_2\ =\ 1.6\ kg
  • Radius of the larger disk =R_2\ =\ 5.0\ cm\ =\ 0.05\ m
  • mass of the hanging block = m = 1.60 kg

Let I be the moment of inertia of the both disk after the welding,\therefore I\ =\ I_1\ +\ I_2\\\Rightarrow I\ =\ \dfrac{1}{2}(M_1R_1^2\ +\ M_2R_2^2)\\\Rightarrow I\ =\ 0.5\times (0.9\times 0.0245^2\ +\ 1.6\times 0.05^2)\\\Rightarrow I\ =\ 2.27\times 10^{-3}\ kgm^2

part (a)

A block of mass m is hanging on the smaller disk,

From the f.b.d. of the block,

Let 'a' be the acceleration of the block and 'T' be the tension in the string.

mg\ -\ T\ =\ mg\\\Rightarrow T\ =\ mg\ -\ ma\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,eqn (1)

Net torque on the smaller disk,

\therefore \tau\ =\ I\alpha\\\Rightarrow TR_1\ =\ \dfrac{Ia}{R_1}\\\Rightarrow T\ =\ \dfrac{Ia}{R_1^2}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,enq (2)

From eqn (1) and (2), we get,

mg\ -\ ma\ =\ \dfrac{Ia}{R_1^2}\\\Rightarrow a\ =\ \dfrac{mg}{\dfrac{I}{R_1^2}\ +\ m}\\\Rightarrow a\ =\ \dfrac{1.60\times 9.81}{\dfrac{2.27\times 10^{-3}}{0.027^2}\ +\ 1.60}\\\Rightarrow a\ =\ 2.91\ m/s^2

part (b)

In this case the mass is rapped on the larger disk,

From the above expression of the acceleration of the block, acceleration is only depended on the radius of the rotating disk,

Let 'a_2' be the acceleration of the block in the second case,

From the above expression,

\therefore a\ =\ \dfrac{mg}{\dfrac{I}{R_1^2}\ +\ m}\\\Rightarrow a\ =\ \dfrac{1.60\times 9.81}{\dfrac{2.27\times 10^{-3}}{0.05^2}\ +\ 1.60}\\\Rightarrow a\ =\ 6.25\ m/s^2

5 0
3 years ago
Other questions:
  • What is the core concept of personality
    10·2 answers
  • Why is the current atomic model called the "electron cloud model?
    8·1 answer
  • What is the velocity of a beam of electrons that goes undeflected when passing through perpendicular electric and magnetic field
    14·1 answer
  • a man pushes on a wall with a force of 50N. what are the size and direction of the force that the wall exert on the man?
    10·1 answer
  • A fighter jet travels 10km at an angle of 30 degrees. He then turns sharply and flies 25 km at an angle of 75 degrees. What is t
    8·1 answer
  • Answer this plzzzzzzzzzzzzz
    8·1 answer
  • 11. You are in the frozen food section of the grocery store and you notice that your hand gets cold when you place it on the gla
    7·1 answer
  • PLEASE ANSWER IF YOU CAN AND NOT FOR THE SAKE OF GAINING POINTS!
    11·1 answer
  • A 90-kg skydiver jumps from a height of 6000 m above the ground, falling head-first (pike position). The area of the diver is 0.
    6·1 answer
  • Which force below does the most work? All three displacements are the same. The 10 N force. The 8 N force The 6 N force. They al
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!