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
Dima020 [189]
3 years ago
9

An 1876 N crate is being pushed across a level force at a constant speed by a force of 747 N. What is the coefficient of kinetic

friction?
0.16
0.40
0.08
not enough information
Physics
1 answer:
nekit [7.7K]3 years ago
8 0

The crate only moves horizontally, so its net vertical force is 0. The only forces acting in the vertical direction are the crate's weight (pointing downward) and the normal force of the surface on the crate (pointing upward). By Newton's second law, we have

∑ <em>F</em> (vertical) = <em>n</em> - <em>mg</em> = 0   →   <em>n</em> = <em>mg</em> = 1876 N

where <em>n</em> is the magnitude of the normal force.

In the horizontal direction, the crate is moving at a constant speed and thus with no acceleration, so it's completely in equilibrium and the net horizontal force is also 0. The only forces acting on it in this direction are the 747 N push (pointing in the direction of the crate's motion) and the kinetic friction opposing it (pointing in the opposite direction). By Newton's second law,

∑ <em>F</em> (horizontal) = 747 N - <em>f</em> = 0   →   <em>f</em> = 747 N

The frictional force is proportional to the normal force by a factor of the coefficient of kinetic friction, <em>µ</em>, such that

<em>f</em> = <em>µn</em>   →   <em>µ</em> = <em>f</em> / <em>n</em> = (747 N) / (1876 N) ≈ 0.398188 ≈ 0.40

You might be interested in
Adding a best-fit line to the scatter plot shown below would be an example of _____.
baherus [9]
I think It would be C. Checking a prediction. Sorry if I’m wrong
3 0
3 years ago
Read 2 more answers
This exercise uses the radioactive decay model. After 3 days a sample of radon-222 has decayed to 58% of its original amount. (a
Vadim26 [7]

Answer: a) 3.85 days

b) 10.54 days

Explanation:-

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  = ?

t = time taken for decomposition  = 3 days

a = let initial amount of the reactant  = 100 g

a - x = amount left after decay process  = \frac{58}{100}\times 100=58g

First we have to calculate the rate constant, we use the formula :

Now put all the given values in above equation, we get

k=\frac{2.303}{3}\log\frac{100}{58}

k=0.18days^{-1}

a) Half-life of radon-222:

t_{\frac{1}{2}}=\frac{0.693}{k}

t_{\frac{1}{2}}=\frac{0.693}{0.18}=3.85days

Thus half-life of radon-222 is 3.85 days.

b) Time taken for the sample to decay to 15% of its original amount:

where,

k = rate constant  = 0.18days^{-1}

t = time taken for decomposition  = ?

a = let initial amount of the reactant  = 100 g

a - x = amount left after decay process  = \frac{15}{100}\times 100=15g

t=\frac{2.303}{0.18}\log\frac{100}{15}

t=10.54days

Thus it will take 10.54 days for the sample to decay to 15% of its original amount.

3 0
3 years ago
An uncharged capacitor is connected to a 21-V battery until it is fully charged, after which it is disconnected from the battery
attashe74 [19]

Answer:

The voltage bewtween the plates will be 9.5V

Explanation:

Facts:

The capacitance of a parallel plate capacitor having plate area A and plate separation d is C=ϵ0A/d.  

Where ϵ0 is the permittivity of free space.  

A capacitor filled with dielectric slab of dielectric constant K, will have a new capacitance C1=ϵ0kA/d

        C1=K(ϵ0A/d)

        C1=KC   ----------- 1

Where C is the capacitance with no dielectric and C1 is the capacitance with dielectric.

The new capacitance is k times the capacitance of the capacitor without dielectric slab.  

This implies that the charge storing capacity of a capacitor increases k times that of the capacitor without dielectric slab.

Given points

• The terminal voltage of the battery to which the capacitor is connected to charge V=25V

• A dielectric slab of paraffin of dielectric constant K=2  is inserted in the space between the capacitor plates after the fully charged capacitor is disconnected

The charge stored in the original capacitor Q=CV

The charge stored in the original capacitor after inserting dielectric Q1=C1V1

The law of conservation of energy states that the energy stored is constant:

i.e Charge stored in the original capacitor is same as charge stored after the dielectric is inserted.

Q   =  Q1

CV = C1V1

  CV = C1V1  -------2

We derived C1=KC from equation 1. Inserting this into equation 2

   CV = KCV1

 V1 = (CV)/KC

         V/K

       = 21/2.2

      = 9.5

4 0
3 years ago
What is the equation used to calculate the total amount of energy used by an appliance?
charle [14.2K]

Answer:

Power = Current × Voltage

Explanation:

Units:

Power = Watts

Current = Àmperes

Voltage = Volts

8 0
3 years ago
What gas law looks at the relationship between pressure and temperature of a gas? A) Boyle's Law B) Charles' Law C) Gay Lussac's
Mandarinka [93]

Answer: it should be Boyle’s law

Explanation:

6 0
3 years ago
Read 2 more answers
Other questions:
  • What velocity vector will move you 200 miles east in 4 hours traveling at a constant speed?
    6·1 answer
  • Calculate the impulse imparted when a 3,000-kg car hits a wall at 60 . m/s and comes to a stop.
    6·1 answer
  • Help please, what does gravitational force do according to these answer choices?
    5·1 answer
  • Maximum power transfer theorem iz related to which chapter of physics<br> Class 12
    13·1 answer
  • Two cars are traveling along a straight line in the same direction, the lead car at 24.7m/s and the other car at 29.9m/s. at the
    6·1 answer
  • The name of the Sl unit for force is the ___?<br><br> A. Joule<br> B. Newton<br> C.Watt
    13·2 answers
  • T02.5 Quiz: Reaction Rates
    15·1 answer
  • A cannon sitting on level ground is aimed at 45.0 degrees relative to the horizontal. It fires a test shot at a target located 1
    12·1 answer
  • we know if we apply the force along the left, friction acts along the right and vice versa.But what about an object which is not
    12·1 answer
  • A stun gun or TASER is designed to put out a few seconds worth of electric pulses that impress a
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!