The place where potential energy is zero is
a) At height equal to double the radius of the earth
b) At infinity
c) At a height equal to half the radius of the earth
d) At a depth equal to 1/3 radius of the earth​

Explanation:

70N-40N=30N

A. 30 m/s . . . speed

B. 30 m to the East  . . . displacement

C. 30 m/s to the East  . . . velocity

D. 30 m . . . distance

Answer:

Explanation:

Given

Height S = 8.4m

Initial velocity u = 24m/s

Required

Time it will take to reach the ground

Using the equation of motion

S = ut +1/2gt²

8.4 = 24t + 1/2(9.8)t²

8.4 = 24t+4.9t²

4.9t²+24t - 8.4 = 0

Multiply through by 10

49t²+240t-84 = 0

Factorize

t = -240±√240²-4(49(-84)/2(49)

t = -240±√57600+16464/98

t = -240±√74064/98

t = -240±272.15/98

t = 32.15/98

t = 0.328seconds

Hence it takes 0.328seconds before it lands on the ground below.

b) The horizontal distance is the range expressed as;

R = u²/g

R = 27²/9.8

R = 729/9.8.

R = 74.39m

a. The time it took before the motorcycle stunt driver lands on the ground below is 1.31 seconds.

b. The distance from the base of the cliff that the motorcycle stunt driver traveled while in  the air is 31.44 meters.

Given the following data:

We know that the acceleration due to gravity (g) of an object on planet Earth is equal to 9.8 [tex]m/s^2[/tex]

a. To determine how long (time) it took before the motorcycle stunt driver lands on the ground below:

At maximum height, time is given by the formula:

[tex]Time = \sqrt{\frac{2H}{g} }[/tex]

Where:

Substituting the given parameters into the formula, we have;

[tex]Time = \sqrt{\frac{2\times 8.4}{9.8} }\\\\Time = \sqrt{\frac{16.8}{9.8} }\\\\Time =\sqrt{1.7413}[/tex]

Time = 1.31 seconds.

b. To determine how far (distance) away from the base of the cliff the motorcycle stunt driver traveled while in  the air:

[tex]Horizontal\;distance = horizontal\;speed \times time\\\\Horizontal\;distance = 24 \times 1.31[/tex]

Horizontal distance = 31.44 meters.

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Use the definition of average acceleration:

a = ∆v / t

If v is the starting speed, then ∆v = 0 - v, so solve for v :

-6.42 m/s² = (0 - v) / (2.85 s)

v = (6.42 m/s²) (2.85 s)

v ≈ 18.3 m/s

Answer:

D

Explanation:

I took the test

The procedure that would best demonstrate that moving magnet causes an electric current to flow in a wire coil is connect a wire coil to an ammeter. Move a bar magnet into and out of the wire coil as you observe the ammeter. The correct option is D.

The flow of electricity in an electronic circuit, as well as the amount of electricity flowing through a circuit, are referred to as electric current. It is expressed in amperes (A).

The greater the value in amperes, the more electricity flows through the circuit.

When an electron is introduced into a wire, a free electron is attracted to a proton in order to be neutral.

Forcing electrons out of their orbits can result in an electron shortage. Electric current is the continuous movement of electrons in a wire.

Connecting a wire coil to an ammeter is the best way to demonstrate that a moving magnet causes an electric current to flow in a wire coil. As you watch the ammeter, move a bar magnet in and out of the wire coil.

Thus, the correct option is D.

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Answer:

The reason why it is important that all the airplanes have the same design is that the students first test is an experiment to determine the effect of the paper kind on the distance the airplane flies

The first experiment, therefore measures the effect of the independent variable, which is the kind of paper on the dependent variable, which is how far the paper flies

The constant or the factor held constant in the experiment is the design of the airplane, so as to ensure that changes in the distance flown by the airplane are due to the changes in the kind of paper alone

Explanation:

Answer:

1) The velocity of the ball return to the thrower's hand is -15 meters per second.

2) The resulting velocity of the boat is [tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex].

Explanation:

1) Let suppose that ball experiments a free fall, that is an uniform accelerated motion, in which effects from gravity and Earth's rotation can be neglected. The velocity of the ball is represented by the following equations of motion:

Position

[tex]v_{o}\cdot t -\frac{1}{2}\cdot g\cdot t^{2} = 0[/tex]

[tex]t\cdot \left(v_{o}-\frac{1}{2}\cdot g\cdot t \right) = 0[/tex] (1)

Velocity

[tex]v = v_{o}-g\cdot t[/tex] (2)

Where:

[tex]t[/tex] - Time, measured in seconds.

[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.

[tex]v_{o}[/tex] - Initial velocity of the ball, measured in meters per second.

[tex]v[/tex] - Final velocity of the ball, measured in meters per second.

From (1), we get the time when the ball returns to the thrower's hand:

[tex]v_{o}-\frac{1}{2}\cdot g\cdot t = 0[/tex]

[tex]t = \frac{2\cdot v_{o}}{g}[/tex]

And then we apply this result in (2):

[tex]v = v_{o}-g\cdot \left(\frac{2\cdot v_{o}}{g} \right)[/tex]

[tex]v = -v_{o}[/tex] (3)

Then, the velocity of the ball return to the thrower's hand is -15 meters per second.

2) The resulting velocity of the boat ([tex]\vec v_{B}[/tex]) is represented by the vectorial sum of the velocity of the boat relative to the river ([tex]\vec v_{B/R}[/tex]) and the velocity of the river ([tex]\vec v_{R}[/tex]), both measured in meters per second, that is:

[tex]\vec v_{B} = \vec v_{R}+\vec {v}_{B/R}[/tex] (4)

If we know that [tex]\vec v_{R} = 6\,\hat{i}\,\left[\frac{m}{s} \right][/tex] and [tex]\vec v_{B/R} = 18\,\hat{j}\,\left[\frac{m}{s} \right][/tex], then the resulting velocity of the boat is:

[tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex]

The resulting velocity of the boat is [tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex].

Answer:

The force to get the plane moving, and to balance the friction so it does not stop, is provided by the propeller. However, the wheels provide the acceleration of the car.

Explanation:

Answer:

053.

Explanation:

Given that the radius of curvature of the path, R = 75 m.

Speed of the car on that path , [tex]v_1 = 35 m/s[/tex]

The centripetal force,[tex]F_c[/tex] acting on the body having mass, m, when it moves with the velocity v  on curved path having radiusR

Ris[tex]F_c = mv^2/R[/tex]

Gravitational force, [tex]F_g[/tex] = mg.

Let tha angle of superelevation is [tex]\theta.[/tex]

As the car does not skid even with zero friction, so

[tex]mg\sin\theta = (mv_1^2)/2 \cos\theta[/tex]

[tex]\Rightarrow \tan\theta = v_1^2/2g=\cdots(i)[/tex]

On sunny day, let the minimun static friction coefficient between the wheels and the pavement is [tex]\mu.[/tex]  

As [tex]v_2[/tex] = 118 m/s is greater than   v_so the car tends to skid in upper direction and the frictional

force,f, will acts is downward direction.

As there is no skidding, so

[tex]f+ mg\sin\theta= (m(v_2)^2)/R\cos\theta[/tex]

[tex]\Rightarrow f=(m(v_2)^2)/R\cos\theta - mg\sin\theta[/tex]

where [tex]f= \mu N.[/tex]

[tex]So, \mu = \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{N} \cdots(ii)[/tex]

Where N is the normal reaction can be determined by balancing the force in perpendicular direction of the plane.

[tex]N= mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta[/tex]

From equation (ii)

[tex]\mu = \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta}[/tex]

[tex]=\frac{-g\tan\theta+v^2/R}{v_2^2\tan\theta+g}[/tex]

[tex]= \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta}[/tex]

[tex]=\frac{-g(v_1^2/2g)+v^2/R}{v_2^2(v_1^2/2g)+g}[/tex]

[tex]= \frac{v_2^2/R-v_1^2/R}{g+v_2^2/R\times v_1^2/Rg}[/tex]

[tex]=\frac{118^2/75-35^2/75}{9.81+118^2/75\times 35^2/(75\times 9.81)}[/tex]

=0.53

Hence, the minimum coefficient of friction is 0.53.

Answer:

The one that is 100 cm from the center.

Explanation:

Given that merry-go-round means moving at uniform circular motion or constant angular speed. Hence the person who is closer to the center is moving at a slower speed, while the one far away from the center has a larger linear speed because he has moved a long distance in the same amount of time, despite being on these objects.

To illustrate

A with the 50 cm

B with the 100 cm

Hence, to get speed, we have

A = 2 * pi * 50 / T

B = 2 * pi * 100 / T

And by the explanation of angular speed

We have w = 2*pi/T where w is the angular speed in radians/s

Hence we have

A = 50w

B = 100w

Therefore, the one that is 100 cm from the center has a larger linear speed.

Answer:

60 km per hour

Explanation:

if you drive for 30 min and go 30km then if you drive for 60 min(1hr) then you would have driven 60km.

Answer:

60

Explanation:

hope this helps

Answer:

This question is incomplete, a possible question would be to calculate the work done by the ball.

Work done = 8J

Explanation:

Work done by an object is calculated my multiplying the force by the distance.

The weight of this ball is 2.0N, which also represents the force exerted by the ball. The ball travels through a distance of 4m

Hence, work done = F × d

Work done = 2N × 4m

Work done = 8Nm or 8J

Answer: used concepts to simplify and order the world around us, categories: objects, events, ideas, or people

hierarchies: subdivide categories into smaller more detailed units, prototypes: best example

algorithm: time-consuming but thorough set of rules or procedures

heuristics: simpler way of thinking, solve problems but maybe incorrect solutions

insight: flash of inspiration that solves problem

representativeness heuristic: judge likelihood of things in terms of how they represent our prototype

availability heuristic: judge likelihood of things based on how vivid they are or how readily they come to mind.

Explanation: i hope that helped!

Answer:

SI

Explanation:

Answer:

Their function is to produce sound by allowing the free edges of the folds to vibrate against one another and also to act as the laryngeal sphincter when they are closed.

Answer:

The resultant displacement of the airplane in 4 hours is 212.8 km.

Explanation:

The components of the airplane's velocity and wind's velocity are:

Airplane:

[tex] v_{a_{x}} = v_{a}cos(45) = 70 km/h*cos(45) = 49.50 km/h [/tex]

[tex] v_{a_{y}} = v_{a}sin(45) = 70 km/hsin(45) = 49.50 km/h [/tex]

Wind:

[tex] v_{w_{x}} = 0 [/tex]

[tex] v_{w_{y}} = v_{w} = -30 km/h [/tex]

Now, to know the new velocity of the airplane we to find the result vector:

[tex] v_{x} = v_{a_{x}} + v_{w_{x}} = 49.50 km/h + 0 = 49.50 km/h [/tex]

[tex]v_{y} = v_{a_{y}} + v_{w_{y}} = 49.50 km/h - 30 km/h = 19.50 km/h[/tex]  

Now, the magnitude of the new speed of the airplane is:

[tex] v_{a} = \sqrt{v_{x}^{2} + v_{y}^{2}} = \sqrt{(49.50 km/h)^{2} + (19.50 km/h)^{2}} = 53.20 km/h [/tex]

Finally, after 4 hours the resultant displacement of the airplane is:

[tex] x = v*t = 53.20 km/h*4 h = 212.8 km [/tex]

Therefore, the resultant displacement of the airplane in 4 hours is 212.8 km.

I hope it helps you!                                        

Answer:

trenchs and magma

Explanation:

Answer: Ridges form along cracks (divergent boundaries) in the oceanic crust (Molten rock (magma) rises through these cracks and pushes to both sides. When it cools, it forms new oceanic crust. The old crust is pushed away and new crust takes over. This is called Sea-Floor Spreading.

Small gaps which function as expansion joints are deliberately left between the rail ends to allow for expansion of the rails in hot weather. ... Because of these small gaps, when trains pass over jointed tracks they make a "clickety-clack" sound.

In physics, the triangle symbol (∆) typically represents a change or difference in a particular quantity.



A triangle is often used to denote the difference between two values of a variable. For example, if we have two values of time, t1 and t2, the change or difference in time can be represented as Δt = t2 - t1, where Δt is the triangle symbol indicating the change in time. Similarly, it can be used to represent differences in other physical quantities such as displacement (∆x), velocity (∆v), or temperature (∆T). The triangle symbol (∆) is a shorthand notation commonly used in physics to indicate changes or differences.

In terms of change in displacement, the triangle symbol (∆) represents the difference between two positions or locations. It indicates the change in the object's position from an initial point to a final point.

For example, if an object initially starts at position x1 and then moves to position x2, the change in displacement (∆x) can be calculated as ∆x = x2 - x1. Here, ∆x represents the difference or change in the object's displacement.

The magnitude of ∆x gives the overall distance traveled by the object, and its sign indicates the direction of the displacement. A positive ∆x signifies a displacement in the positive direction (e.g., to the right or upward), while a negative ∆x represents a displacement in the negative direction (e.g., to the left or downward).

Therefore, The triangle symbol (∆) is commonly used in physics equations to denote changes or differences in various quantities, including displacement, velocity, time, and more. It helps us analyze and quantify the differences between two values of a physical quantity.

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Answer:

  a = 7.5 m / s²

Explanation:

For this exercise let's use Newton's second law, let's create a coordinate system with the x axis parallel to the plane and the y axis perpendicular to the plane

Y axis

       N - W cos θ = 0

       N = mg cos θ

X axis

       W sin θ = m a

       mg sin θ = m a

        a = g sin θ

let's calculate

        a = 9.8 cos 40

        a = 7.5 m / s²

Answer:

Explanation:

Initial velocity , u = 27 m/s

displacement before stop,  s = 41.5 m .

final velocity,  v = 0

acceleration a = ?

v² = u² + 2 a s

0 = 27² + 2 x a x 41.5

a = - 27² / 2 x 41.5

= - 8.78 m /s

Answer: b) A positive charge is moved toward a positive charge.

Answer:

0.5m/s2

..............

Answer:

Uniform Speed: A body is said to be moving with uniform speed, if it covers equal distances in equal intervals of time. Variable Speed: A body is said to be moving with variable speed if it covers unequal distances in equal intervals of time.

Explanation:

I got it from google

Answer:

Speed is a measure of how fast an object is moving at a given instant of time. It is a scalar quantity. Its unit is m/s. For a body covering equal distances in equal time intervals, the speed is called uniform speed.

Explanation:

Answer:........... .. .....

The answer is option c - It will divide in half to form two new cells..

Explanation:

The sentence that best describes what happened during cell growth is ;

( D ) It will become larger by taking in nutrients

As the yeast cells begin to grow ( i.e. cell growth ), they will require more nutrients and as they take in the necessary nutrients they will gradually increase in size ( becoming larger ) which is a vital sign of cell growth and development, which will be seen in the yeast cells as they undergo cell growth.

The production of offsprings with a mate does not describe an activity that occurs in cell growth.  

Hence we can conclude that The sentence that best describes what happened during cell growth is, It will become larger by taking in nutrients.

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