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
raketka [301]
3 years ago
5

An object with a mass M = 250 g is at rest on a plane that makes an angle θ = 30 o above the horizontal. The coefficient of kine

tic friction between M and the plane is μk = 0.100. Mass M is attached by a string to another mass, m = 200 g, which hangs freely. When mass m has fallen 30.0 cm, its speed is:
(A) 83 cm/s
(B) 59 cm/s
(C) 160 cm/s
(D) 72 cm/s
(E) 48 cm/s
Physics
1 answer:
liubo4ka [24]3 years ago
3 0

Answer:

v = 79.2 m/s

Solution:

As per the question:

Mass of the object, m = 250 g = 0.250 kg

Angle, \theta = 30^{\circ}

Coefficient of kinetic friction, \mu_{k} = 0.100

Mass attached to the string, m = 0.200 kg

Distance, d = 30 cm = 0.03 m

Now,

The tension in the string is given by:

Mgsin\theta + \mu_{k}Mgcos\theta + Ma = T        (1)

Also

T = m(g + a)

Thus eqn (1) can be written as:

Mgsin\theta + \mu_{k}Mgcos\theta + Ma = m(g - a)

Mgsin\theta + \mu_{k}Mgcos\theta + Ma = mg + ma

mg - Mgsin\theta - \mu_{k}Mgcos\theta = (M - m)a

a = \frac{0.2\times 9.8 - 0.250\times 9.8\times sin30^{\circ} - 0.1\times 0.250\times 9.8\times cos30^{\circ}}{0.250 - 0.200}

a = 10.45\ m/s^{2}

Now, the speed is given by the third eqn of motion with initial velocity being zero:

v^{2} = u^{2} + 2ad

where

u = initial velocity = 0

Thus

v = \sqrt{2ad}

v = \sqrt{2\times 10.45\times 0.03} = 0.792\ m/s

You might be interested in
How and why does air pressure change with altitude in the atmosphere?
wlad13 [49]
Pressure with Height: pressure decreases with incrementing altitude. The pressure at any caliber in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a homogeneous surface at lower calibers.
5 0
3 years ago
A solenoid has a radius Rs = 14.0 cm, length L = 3.50 m, and Ns = 6500 turns. The current in the solenoid decreases at the rate
babymother [125]

Answer:

E = 58.7 V/m

Explanation:

As we know that flux linked with the coil is given as

\phi = NBA

here we have

A = \pi R_s^2

B = \mu_o N i/L

now we have

\phi = N(\mu_o N i/L)(\pi R_s^2)

now the induced EMF is rate of change in magnetic flux

EMF = \frac{d\phi}{dt} = \mu_o N^2 \pi R_s^2 \frac{di}{dt}/L

now for induced electric field in the coil is linked with the EMF as

\int E. dL = EMF

E(2\pi r_c) = \mu_o N^2 \pi R_s^2 \frac{di}{dt}/L

E = \frac{\mu_o N^2 R_s^2 \frac{di}{dt}}{2 r_c L}

E = \frac{(4\pi \times 10^{-7})(6500^2)(0.14^2)(79)}{2(0.20)(3.50)}

E = 58.7 V/m

3 0
3 years ago
Assume the radius of an atom, which can be represented as a hard sphere, is r = 1.95 Å. The atom is placed in a (a) simple cubic
Nuetrik [128]

Answer:

(a) A = 3.90 \AA

(b) A = 4.50 \AA

(c) A = 5.51 \AA

(d) A = 9.02 \AA

Solution:

As per the question:

Radius of atom, r = 1.95 \AA = 1.95\times 10^{- 10} m

Now,

(a) For a simple cubic lattice, lattice constant A:

A = 2r

A = 2\times 1.95 = 3.90 \AA

(b) For body centered cubic lattice:

A = \frac{4}{\sqrt{3}}r

A = \frac{4}{\sqrt{3}}\times 1.95 = 4.50 \AA

(c) For face centered cubic lattice:

A = 2{\sqrt{2}}r

A = 2{\sqrt{2}}\times 1.95 = 5.51 \AA

(d) For diamond lattice:

A = 2\times \frac{4}{\sqrt{3}}r

A = 2\times \frac{4}{\sqrt{3}}\times 1.95 = 9.02 \AA

6 0
3 years ago
In lecture, it was discussed measurements of mass, temperature, time, volume and length. which of these is not an si base unit (
photoshop1234 [79]

From the options provided in the question, the measurement which is not an SI base unit is volume.

<h3>What is SI base unit?</h3>

This is referred to as the standard and fundamental unit of measurement of various quantities or variables which is defined arbitrarily and not by combinations of other units.

Volume is a quantity which is derived from the combination of lengths in a  three-dimensional manner which is why the formula is length× breadth×height and the unit is cm³. This is gotten from the combination of the unit of length which is cm.

This is therefore the reason why volume was chosen as the most appropriate choice.

Read more about Volume here brainly.com/question/463363

#SPJ1

6 0
1 year ago
Induced EMF and Current in a Shrinking LoopShrinking Loop. A circular loop of flexible iron wire has an initial circumference of
vodomira [7]

Answer:

Explanation:

Let c be the circumference and r be the radius

c = 2πr , r = c / 2π , area A = π r² = π (c/2π )²  = (1/4π) x c²

flux (ψ) = BA = 1 X 1/4π X c²

dψ/dt = 1/4π x 2c dc/dt =1/2π x c x dc/dt

at t = 8 s

c = 161 - 13 x 8 = 57 cm , dc/dt = 13 cm/s  

e = dψ/dt = (1 / 2π )x 57 x 13 x 10⁻⁴ = 118 x 10⁻⁴ V.

4 0
3 years ago
Other questions:
  • A ball is attached to the end of a massless string. A circus clown twirls the string with a pulling force of 12 N, and the ball
    11·2 answers
  • Will the decimal point be moving to the right or to the left? How do you know?
    15·1 answer
  • True of false all matter requires it’s own space
    5·1 answer
  • Which of the following states that all matter tends to "warp" space in its vicinity and that objects react to this warping by ch
    6·1 answer
  • Is a mirror transparent, translucent or opaque?
    8·2 answers
  • Why is chlorine bonded by a single covalent bond, but Oxygen bonded by a double covalent bond?
    15·1 answer
  • Which fact is true during a fission chain reaction?
    5·1 answer
  • PLS HELP!!
    12·2 answers
  • The transfer of energy when particles of a fluid move from one place to another is called
    14·1 answer
  • How do characteristics help you to classify seeds?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!