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
Veronika [31]
4 years ago
14

The coefficient of static friction between hard rubber and normal street pavement is about 0.90. On how steep a hill (maximum an

gle) can you leave a car parked?
Physics
2 answers:
jok3333 [9.3K]4 years ago
7 0
First thing to do is to draw the system described above. Then, write an equation for the forces present.
<span>
</span>Σ<span>F = Fg - Ff
</span><span>0 = mgsin</span><span>∅</span><span> - umgcos</span><span>∅</span><span>0 = gsin</span><span>∅</span><span> - ugcos</span><span>∅</span><span>
u = tan</span><span>∅
</span>∅(max) = tan^-1 (u)<span>
</span>
Drupady [299]4 years ago
4 0

Answer: Ok, first, if the mass of the carr is M, and the angle of the hill is a (counting counterclockwise from the ground), the equations for the forces are:

Gravity force Fg = - Mg*sin(a)

Knowing that the normal force that the ground is doing in the car is N = Mg*cos(a)

then the Friction force is: Ff  = 0.9*Mg*cos(a)

if the car is parked, then the sum of the forces must be equal to zero, this is

0.9*Mg*cos(a) - Mg*sin(a) = 0

Mg( 0.9*cos(a) - sin(a)) = 0

so

0.9*cos(a) = sin(a)

0.9 = sin(a)/cos(a) = Tg(a)

a = aTg(0.9) = 41.9°

so the maximum angle is 41.9°, if is smaller or equal, then your car will be fine.

You might be interested in
42,43 and 44 please
Mariana [72]
42) The sailboat travels east with velocity v_e=30 mph, while the current moves south with speed v_s=30 mph. Since the two velocities are perpendicular to each other, he resultant velocity will be given by the Pytagorean theorem:
v= \sqrt{v_e^2+v_s^2}= \sqrt{(30)^2+(30)^2}=42 mph
and the direction is in between the two original directions, therefore south-east. So, the correct answer is
D) 42 mph southeast

43) Since the light moves by uniform motion, we can calculate the distance corresponding to one light year by using the basic relationship between velocity, space and time. In fact, we know the velocity:
v=300,000,000 m/s=3 \cdot 10^8 m/s
and the time is one year, corresponding to:
t=32,000,000 s=3.2 \cdot 10^7 s
therefore, the distance corresponding to one light year is:
S=vt=(3\cdot 10^8 m/s)(3.2 \cdot 10^7 s)=9.6 \cdot 10^{15}m
Therefore, the correct answer is D.

44) For the purpose of the problem, we can assume that the light travels instantaneously from the flash to us (because the distances involved are very small), so the time between the flash and the thunder corresponds to the time it took for the sound to travel to us.
The speed of sound is
v=1100 ft/s=750 mph=335 m/s
And since the time between the flash and the thunder is t=3 s, the distance is
S=vt=(335 m/s)(3 s)=1005 m=0.62 miles
Therefore, the correct answer is A) 3/5 mile.
6 0
3 years ago
Why is there no overall electrical charge on an aluminium atom?
uranmaximum [27]
The electrical charge of particles. The total number of electrons in an atom is always the same as the number of protons in the nucleus. This means atoms have no overall electric charge. The number of protons in an atom is called its atomic hater number.
4 0
4 years ago
Read 2 more answers
a 200 kg crate is pushed horizontally with a force of 700 N. If the coefficient of friction is 0.2 calculate the acceleration of
Crazy boy [7]

Answer:

a=1.54\ m/s^2

Explanation:

<u>Net Force</u>

The Second Newton's law states that an object acquires acceleration when an external unbalanced net force is applied to it.

That acceleration is proportional to the net force and inversely proportional to the mass of the object.

It can be expressed with the formula:

\displaystyle a=\frac{F_n}{m}

Where

Fn = Net force

m  = mass

The m=200 kg crate is pushed horizontally with a force Fa=700 N. The friction force opposes motion and a horizontal net force appears causing the acceleration.

The forces on the vertical direction are in balance since the crate does not accelerate in that direction, thus the weight and the normal force are equal:

N = W = mg

The friction force can be calculated by using the coefficient of friction μ:

F_r=\mu N

Calculating the normal force:

N = 200 * 9.8 = 1,960 N

The friction force is:

F_r=0.2*1,960

F_r=392\ N

The horizontal net force is:

F_n = F_a-F_r=700\ N - 392\ N

F_n = 308\ N

Finally, the acceleration is computed:

\displaystyle a=\frac{308}{200}

\boxed{a=1.54\ m/s^2}

3 0
3 years ago
Two parallel metal plates are at a distance of 8.00 m apart.The electric field between the plates is uniform directed towards th
yuradex [85]

Answer:

C

Explanation:

Formula E=F/C also E=V/d

In this case use the second formula; E=V/d

Data given; E=4N/C d=8m

So v=E X d

     V=4x8=32V

k.e=eV= 2X32=64eV

3 0
4 years ago
What type of equilibrium is guaranteed by each condition of equilibrium
Ostrovityanka [42]

Answer: Conditions for equilibrium require that the sum of all external forces acting on the body is zero (first condition of equilibrium), and the sum of all external torques from external forces is zero (second condition of equilibrium). These two conditions must be simultaneously satisfied in equilibrium

Explanation: Hope this helped

5 0
3 years ago
Other questions:
  • The average distance from earth to the sun is 1 au. <br><br> a. True <br><br> b. False
    12·1 answer
  • An early submersible craft for deep-sea exploration was raised and lowered by a cable from a ship. When the craft was stationary
    9·2 answers
  • Gretchen runs the first 4.0 km of a race at 5.0 m/s. Then a stiff wind comes up, so she runs the last 1.0 km at only 4.0 m/s.
    9·1 answer
  • PLS ANSWER QUICKLY!!!! 15 POINTS
    5·1 answer
  • A key lime pie in a 10.00 inch diameter plate is placed upon a rotating tray. Then, the tray is rotated such that the rim of the
    5·1 answer
  • A ball is thro.d hit the grouvelocity)?
    13·1 answer
  • Which data set has the largest range?
    12·2 answers
  • When a force is applied to a wheel, its axle exerts a greater force?
    5·1 answer
  • The rate of change of velocity is called:.
    7·1 answer
  • (PLEASE HURRY)
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!