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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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The path of a launched missile can be modeled by a quadratic function. Explain how you would use the function to determine the g

bixtya [17]

Answer:

$h_{max}$ =u^2/2a

s=ut

Explanation:

The path of a launched missile can be modeled by a quadratic function. Explain how you would use the function to determine the greatest height the rocket reaches and the horizontal distance it travels before reaching the ground. Answer in complete sentences.

from the newton's equation of motion , we can use the equation

s=ut+1/2at^2

s=h

a=g

g=acceleration due to gravity

t=time

u=initial velocity

h=height of the launched missile

the vertical component of the flight of the missile should be

h=1/2at^2, notice that it is going travelling against gravity

also V^2=u^2+2ah

at maximum height , final velocity becomes zero

-u^2=-2ah

u= $\sqrt{2ah}$

or $h_{max}$ =u^2/2a

take not that the initial velocity has both a vertical component and horizontal component,

s=ut+1/2at^2

to get the horizontal distanced moved , we write

s=ut.....................

time is independent on the horizontal and vertical component

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3 years ago

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3 years ago

Two long, parallel wires are separated by a distance of 3.30 cm. The force per unit length that each wire exerts on the other is

castortr0y [4]

Answer with Explanation:

We are given that

Distance between two parallel long wires=r=3.3 cm= $\frac{3.3}{100}=0.033m$

1 m=100 cm

$\frac{F}{l}=5\times 10^{-5} N/m$

$I_1=0.62 A$

a.We have to find the current in the second wire.

We know that

$\frac{F}{l}=\frac{2\mu_0I_1I_2}{4\pi r}$

Using the formula

$5\times 10^{-5}=\frac{2\times 10^{-7}\times 0.62\times I_2}{0.033}$

Where $\frac{\mu_0}{4\pi}=10^{-7}$

$I_2=\frac{5\times 10^{-5}\times 0.033}{2\times 10^{-7}\times 0.62}$

$I_2=13.3 A$

Hence, the current in the second wire=13.3 A

b.We are given that the wires repel each other.When the current carrying in the wires in opposite direction then, the wires repel to each other.

Hence,the two currents in opposite directions.

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3 years ago

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lina2011 [118]

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