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
Basile [38]
3 years ago
11

A friend claims that her car can accelerate from a stop to 60 mi/h (26.8 m/s) in 5.1 s , but the speedometer is broken. You deci

de to test her claim by riding with her, and you bring along a small metal washer, a short length of string, a protractor, and a pen that can write on glass. Sitting in the passenger seat, you tie the washer to one end of the string and then let the string-washer combination hang straight down by rolling up the passenger-door window to pinch the free end of the string. While the car is stationary, you draw a line on the window alongside the vertical string.
How large is the angle the string makes with the line you drew if the car accelerates at the rate your friend claims?

If an identical washer does not slide on the horizontal dashboard while this is happening, what is the ratio of the frictional force to the gravitational force exerted on this washer?

Physics
1 answer:
Lemur [1.5K]3 years ago
4 0

I attached a diagram, according to the description given, to better understand the problem. The car accelerates, at a 'a' speed, which will also experience the hanging object, in two components:

The one in x, with 'a' in the opposite direction to the car's address

The one found in y, the product of gravity. The two components are related through the tangent and the respective angle, as well,

tan\theta = \frac{ma}{mg}

tan\theta = \frac{a}{g}

To identify, we know that it can be expressed as a function of speed,

a= \frac{\Delta v}{t} = \frac{v-u_0}{5.1}\frac{26.8}{5.1}

a=5.26m/s^2

Replacing in our angle formula,

tan\theta = \frac{5.26}{9.8}

tan\theta = 0.54

\theta = tan^{-1}(0.54)

\theta = 28.4\°

If there is no friction, we consider the vertical forces of both the Washes and the Normal car. So,

F=ma

Therefore the relationship with the vertical component would be given by,

\Rightarrow \frac{F}{mg} = \frac{ma}{mg} = \frac{a}{g}=\frac{5.26}{9.8}=0.54 =54\%

You might be interested in
The magnitude of displacements a and b are 3m and 4m, respectively, c=a+b. What is the magnitude of c if the angel between a and
AysviL [449]

Answer:

(a) 7 m

(b) 1  m

Explanation:

Given:

The magnitude of displacement  vector 'a' is 3 m

The magnitude of displacement vector 'b' is 4 m.

The vector 'c' is the vector sum of vectors 'a' and 'b'.

(a)

Now, when the angle between the vectors is 0°, it means that the vectors are in the same direction. When vectors are in the same direction, then their resultant magnitude is simply the sum of their magnitudes.

So, magnitude of 'c' when 'a' and 'b' are in same direction is given as:

|\overrightarrow c|=|\overrightarrow a|+|\overrightarrow b|\\\\|\overrightarrow c|=3 + 4 = 7\ m

Therefore, the magnitude of vector 'c' is 7 m when angle between 'a' and 'b' is 0°.

(b)

When the angle between the vectors is 180°, it means that the vectors are exactly in the opposite direction. When the vectors are in opposite direction, then their resultant magnitude is the subtraction of their magnitudes.

So, magnitude of 'c' when 'a' and 'b' are in opposite direction is:

|\overrightarrow c|=||\overrightarrow a|-|\overrightarrow b||\\\\|\overrightarrow c|=|3 - 4| = 1\ m

Therefore, the magnitude of vector 'c' is 1 m when angle between 'a' and 'b' is 180°.

4 0
3 years ago
State Archimedes' principle.
vampirchik [111]

Answer:

Archimedes' principle states that, when a body is partially or completely immersed in a fluid, it experiences an apparent loss in weight that is equal to the weight of the fluid displaced by the immersed part of the body.

Explanation:

Archimedes' principle allows the buoyancy of an object partially or fully immersed in a fluid to be calculated. The downward force on the object is simply its weight. Thus, the net force on the object is the difference between the magnitudes

of the buoyant force and its weight. If this net force is positive, the object rises; if negative, the object sinks; and if zero, the object is neutrally buoyant - that is, it remains in place without either rising or sinking. In simple words,

8 0
3 years ago
Read 2 more answers
A car is stopped at a traffic light. When the light turns green at t=0, a truck with a constant speed passes the car with a 20m/
s344n2d4d5 [400]

Answer:

At t = (70 / 3) \; {\rm s} (approximately 23.3 \; {\rm s}.)

Explanation:

Note that the acceleration of the car between t = 0\; {\rm s} and t = 20\; {\rm s} (\Delta t = 20\; {\rm s}) is constant. Initial velocity of the car was v_{0} = 0\; {\rm m\cdot s^{-1}}, whereas v_{1} = 35\; {\rm m\cdot s^{-1}} at t = 20\; {\rm s}\!. Hence, at t = 20\; {\rm s}\!\!, this car would have travelled a distance of:

\begin{aligned}x &= \frac{(v_{1} - v_{0})\, \Delta t}{2} \\ &= \frac{(35\; {\rm m\cdot s^{-1}} - 0\; {\rm m\cdot s^{-1}}) \times (20\; {\rm s})}{2} \\ &= 350\; {\rm m}\end{aligned}.

At t = 20\; {\rm s}, the truck would have travelled a distance of x = v\, t = 20\; {\rm m\cdot s^{-1}} \times 20\; {\rm s} = 400\; {\rm m}.

In other words, at t = 20\; {\rm s}, the truck was 400\; {\rm m} - 350\; {\rm m} = 50\; {\rm m} ahead of the car. The velocity of the car is greater than that of the truck by 35\; {\rm m\cdot s^{-1}} - 20\; {\rm m\cdot s^{-1}} = 15 \; {\rm m\cdot s^{-1}}. It would take another (50\; {\rm m}) / (15\; {\rm m\cdot s^{-1}}) = (10/3)\; {\rm s} before the car catches up with the truck.

Hence, the car would catch up with the truck at t = (20 + (10/3))\; {\rm s} = (70 / 3)\; {\rm s}.

3 0
2 years ago
What variables determine the amount of electrical energy an appliance uses?
Mumz [18]

Answer:

How much electricity the appliance can hold, the number of hours the appliance is used in a day, and how many days it is used of the year.

Explanation:

Once we find all these things its simple math to figure out how many watts the appliance uses.

3 0
2 years ago
Read 2 more answers
A viola string with a fundamental frequency of D4 (293 Hz) is generally tuned using a tension of 49.0 N. However, just before a
Alborosie

Answer:

Explanation:

For fundamental frequency in a vibrating string , the formula is

n = 1 / 2L  x  √ ( T /m₁ )

n is frequency , L is length , T is tension and m₁ is mass per unit length .

For first string ,

293 =  1 / 2L  x  √ ( 49 N  /m₁ )

For second string , let mass per unit length be m₂ .

196 =  1 / 2L  x  √ ( 49 N  /m₂ ) ------ ( 1 )

To bring its frequency back to previous one let tension be T

293  =  1 / 2L  x  √ ( T  /m₂ ) ------- ( 2 )

Dividing

293 / 196 = √ ( T  /49  )

1.4948 = √ ( T  /49  )

2.2344 = T  /49

T = 109.48 N .

8 0
2 years ago
Other questions:
  • What question was asked by Faraday that the narrator calls a leap
    10·2 answers
  • If v lies in the first quadrant and makes an angle Ï/3 with the positive x-axis and |v| = 4, find v in component form.
    5·1 answer
  • If a star is moving away from you at a constant speed, how do the wavelengths of the absorption lines change as the star gets fa
    6·1 answer
  • Which statement is true?
    9·1 answer
  • Satellite a has an orbital radius 3.00 times greater than that of satellite
    9·1 answer
  • Small-plane pilots regularly compete in "message drop" competitions, dropping heavy weights (for which air resistance can be ign
    5·1 answer
  • Calculate the potential required to push eleven amperes through a 20 ohm resistance
    6·2 answers
  • Help ASAP PLEASE.............:3​
    8·1 answer
  • When planning an oral presentation, you want to make sure to do all of the following except _____.
    7·2 answers
  • The volume of an ideal gas changes from 0.40 to 0.55 m3 although its pressure remains constant at 50,000 Pa. What work is done o
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!