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3 years ago

What must the minimum tension of a single?

1 answer:

6 0

Connexus Physics pre-ap semester A final exam, all correct answers. And y’all better be freaking grateful, because it took a long time to type all this out.

1) In the steps of the scientific method…
A. Interpreting results

2) The radius of the Earth is…
B. 6.37 x 10^3 km

3) Which of the following equations best describes…
D. y = 1/2x

4) In the graph, what is the correct description…
C. Negative position

5) The motion of a ball on an inclined plane is described…
C. vi

6) Acceleration due to gravity is also called
C. free-fall acceleration

7) Which of the following is a physical quantity…
A. vector

8) In a coordinate system, a vector is…
A. Cos (theta)

9) Which of the following is an example of projectile motion?
B. a thrown baseball

10) A newton is equivalent to which…
A. kg * m/s^2

11) In the free-body diagram shown below, which of the following…
C. 4050 N

12) A net force of 6.8 N accelerates a 31 kg scooter…
A. 0.22 m/s^2

13) A change in the gravitational force acting…
C. Weight

14) A passenger on a bus moving east sees a man standing on a curb…
C. move west at a speed that is equal to the bus’s speed.

15) In which of the following scenarios is no net work done?
B. A car travels at a constant speed on a flat road.

16) What is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s?
C. 108 J

17) Which of the following refers to the sum of kinetic energy…
D. mechanical energy

18) Which of the following are not units of power?
B. J

19) Which of the following…can be used to…calculate…change in…momentum?
D. (delta)p = F (delta) t

20) Two skaters stand facing…
B. their momenta are equal but opposite.

21) In an inelastic collision…
D. the momentum of one object will increase by the amount that the momentum of the other object decreases.

22) When an object is moving with uniform circular motion…tangential speed
C. is constant

23) Which units would be the most appropriate to use to…
A. newtons

24) How would the speed of Earth’s orbit around the sun change…
A. The speed would not change

25) A girl pushes a box that has a weight of 450 N up an incline…force of 150 N along…
B. 3.0

26) According to the law of conservation of mechanical energy,
C. Total energy must remain the same

27) The potential energy of a 60 kg man…balcony 43 meters…
A. 25000 J

28) If two small beakers of water, one at 70C and one at 80C…
C. The final temperature is between 70C and 80C

29) Why does sandpaper get hot when it is rubbed against rusty metal?
C. Friction between the sandpaper and metal…

30) Which of the following describes a substance in which the temperature and pressure…
D. substance undergoing a change of state

31) An ideal gas system is maintained at a constant volume of 4 L. If pressure is constant…
A. 0 J

32) Which of the following is a thermodynamic process in which a system…
C. a cyclic process

33) When a drop of ink mixes with water…
A The system’s entropy increases, and the total entropy of the universe increases.

34) A mass-spring system can oscillate…
D. elastic potential

35) If a semi-truck decrease its speed from 10 m/s to 5 m/s...
D. ¼ its old kinetic energy

36) A boy releases a small 1 kg toy truck from rest down a 5 meter high hill…
B. 50 J

37) A car accelerates uniformly from 10 m/s to 20 m/s in 4.2 seconds…
A. 2.4 m/s^2

38) What must the minimum tension of a single vertical wire be to support a 1.5 kg picture?
A. 15 N

39) Why does it seem harder to start sliding a couch across a carpeted floor than…
C. The opposing force of friction is greater when an object starts from rest…

40) An elevator weighing 2.00 c 10^5 N is supported by a steel cable…
Fw = mass * gravitational acceleration
2*10^5 = mass * 9.8
mass of the elevator = 20.4*10^3 kg

Fnet = Tension – Fw
mass * acceleration = Tension – 2*10^5
20.4*10^3 * 3 = Tension – 2*10^5
61200 = Tension – 2*10^5
Tension = (61200) + (2*10^5)
Tension = 2.61 * 10^5 newton

41) A bullet with a mass of 6.00 g is fired through a 1.25 kg block of wood on a frictionless surface.
0.006(896) + 0 = 0.006(435) + 1.25(V)
5.376 + 0 = 2.61 + 1.25(V)
5.376 = 2.61 + 1.25(V)
2.766 = 1.25(V)
V = 2.21 m/s

42) Find the final equilibrium temperature when 10.0 g of milk at 10.0C is added to 1.60 x 10^2 g of coffee with a temperature of 90.0C.
Heat lost = heat gained
X = equilibrium temperature
Heat lost = 160(90-x)
Heat gained = 10(x-10)
14400 – 160x = 10x -100
170x = 14500
X = 14500/170
X = 85.25 degrees

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Sound waves that enter the external acoustic meatus eventually encounter the __________, which then vibrates at the same frequen

7nadin3 [17]

Answer:

tympanic membrane (eardrum)

Explanation:

The sound waves spread through the air and reach the outer ear, into which they penetrate through the ear canal. In doing so, they stimulate the eardrum, which closes the inner end of the duct. By vibrating this membrane, the vibration of a chain of ossicles located in the middle ear is induced. These ossicles transmit their vibration to the oval window, which is a membranous structure that communicates the middle ear with the cochlea of the inner ear. When the oval membrane moves, it moves the liquid (perilymph) that fills one of the three cavities of the cochlea generating waves in it. These waves mechanically stimulate the sensory cells (hair cells) located in the organ of Corti, within the cochlea in the central cavity, the middle ramp. This cavity is filled with a liquid rich in K +, endolymph. The cells embedded in the endolymph, change their permeability to K + due to the movement of the cilia and respond by releasing a neurotransmitter that excites the nerve terminals, which initiate the auditory sensory pathway.

3 0

3 years ago

Starting with the definition 1.00 in. = 2.54 cm, find the number of kilometers in 8.00 mi .

velikii [3]

Use Factor-Label Method:

8miles 63360 inches
---------- X --------------------- X
1 1 mile

2.54cm 1 meter
X ------------ X ---------------- X
1 inch 100 cm

1 km
----------------- = 12.87 km
1000meters

8 miles = 12.87 km

8 0

4 years ago

A force, 10 N drags a mass 10 kg on a horizontal table with an acceleration of 0.2

kifflom [539]

Answer:

20&£+)##&843&()-_££-()&_2+0&&-£_!)

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3 years ago

A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, it i

lianna [129]

Answer:

A) the moment of inertia of the system decreases and the angular speed increases.

Explanation:

The complete question is

A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, It is true to say that

A) the moment of inertia of the system decreases and the angular speed increases.

B) the moment of inertia of the system decreases and the angular speed decreases.

C) the moment of inertia of the system decreases and the angular speed remains the same.

D) the moment of inertia of the system increases and the angular speed increases.

E) the moment of inertia of the system increases and the angular speed decreases

In angular momentum conservation, the initial angular momentum of the system is conserved, and is equal to the final angular momentum of the system. The equation of this angular momentum conservation is given as

$I_{1} w_{1} = I_{2} w_{2}$ ....1

where $I_{1}$ and $I_{2}$ are the initial and final moment of inertia respectively.

and $w_{1}$ and $w_{2}$ are the initial and final angular speed respectively.

Also, we know that the moment of inertia of a rotating body is given as

$I = mr^{2}$ ....2

where $m$ is the mass of the rotating body,

and $r$ is the radius of the rotating body from its center.

We can see from equation 2 that decreasing the radius of rotation of the body will decrease the moment of inertia of the body.

From equation 1, we see that in order for the angular momentum to be conserved, the decrease from $I_{1}$ to $I_{2}$ will cause the angular speed of the system to increase from $w_{1}$ to $w_{2}$ .

From this we can clearly see that reducing the radius of rotation will decrease the moment of inertia, and increase the angular speed.

7 0

4 years ago

A kite 100 ft above the ground moves horizontally at a speed of 12 ft/s. at what rate is the angle (in radians) between the stri

Viefleur [7K]

Answer: So this involves right triangles. The height is always 100. Let the horizontal be x and the length of string be z. So we have x2 + 1002 = z2. Now take its derivative in terms of time to get 2x(dx/dt) = 2z(dz/dt) So at your specific moment z = 200, x = 100âš3 and dx/dt = +8 substituting, that makes dz/dt = 800âš3 / 200 or 4âš3. Part 2 sin a = 100/z = 100 z-1 . Now take the derivative in terms of t to get cos a (da./dt) = -100/ z2 (dz/dt) So we know z = 200, which makes this a 30-60-90 triangle, therefore a=30 degrees or Ď€/6 radians. Substitute to get cos (Ď€/6)(da/dt) = (-100/ 40000)(4âš3) âš3 / 2 (da/dt) = -âš3 / 100 da/dt = -1/50 radians

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3 years ago