PLZ HELP!! FOE A TEST

23. Quantities that can be described completely by their magnitude or size are called vector quantities. (5 points)
True
False

Answer:

29.75 revolutions

Explanation:

The kinematic formula for distance, given a uniform acceleration a and an initial velocity v₀, is

[tex]d=v_0t+\frac{1}{2}at^2[/tex]

This car is starting from rest, so v₀ = 0 m/s. Additionally, we have a = 9.2/9.7 m/s² and t = 9.7 s. Plugging these values into our equation:

[tex]d=0t+\frac{1}{2}\left(\frac{9.2}{9.7}\right)(9.7)^2\\d=\frac{1}{2}(9.2)(9.7)\\d=4.6(9.7)\\d=44.62[/tex]

So, the car has travelled 44.62 m in 9.7 seconds - we want to know how many of the tire's circumferences fit into that distance, so we'll first have to calculate that circumference. The formula for the circumference of a circle given its diameter is [tex]c=\pi{d}[/tex], which in this case is 47.8π cm, or, using π ≈ 3.14, 47.8(3.14) = 150.092 cm.

Before we divide the distance travelled by the circumference, we need to make sure we're using the same units. 1 m = 100 cm, so 105.092 cm ≈ 1.5 m. Dividing 44.62 m by this value, we find the number of revs is

[tex]44.62/1.5\approx29.75[/tex] revolutions

Explanation: Newton's first law of motion states that a body at rest remains at rest, or, if in motion, remains in motion at a constant velocity unless acted on by a net external force. This is also known as the law of inertia. Inertia is the tendency of an object to remain at rest or remain in motion.

Answer:

a. The speed of the helicopter at the moment the package is dropped is approximately 15.519 m/s

b. The position of the package 2s after it is dropped is (31.038 m, -9.8 m)

c. The time of flight of the food package is approximately 5.105 seconds

d. The horizontal distance covered is approximately 79.22 m

Explanation:

The given parameters are;

The height at which the helicopter is flying = 125 m

The magnitude of the velocity of the package after 2 seconds, v = 25 m/s

a. The vertical velocity of the package, [tex]v_y[/tex], is given as follows;

[tex]v_y[/tex] = [tex]u_y[/tex] + g·t

Where;

[tex]u_y[/tex] = 0 m/s for the dropped food package

t = The duration of the package in the air = 2 s

g = The acceleration due to gravity = 9.8 m/s²

Therefore;

[tex]v_y[/tex] = g·t = 9.8 m/s² × 2 s = 19.6 m/s

We have,  [tex]v = \sqrt{v_x^2 + v_y^2}[/tex],

Where;

vₓ = The horizontal velocity of the food package = The horizontal speed of the helicopter

therefore, [tex]v_x = \sqrt{v^2 - v_y^2}[/tex], which gives;

[tex]v_x = \sqrt{v^2 - v_y^2} = \sqrt{25^2 - 19.6^2} \approx 15.519 \ m/s[/tex]

The speed of the helicopter at the moment the package is dropped ≈ 15.519 m/s

b. The vertical if the package after 2 s is given as follows;

The vertical position of the package after 2 s is given by the kinematic equation, h = 1/2·g·t² = 1/2 × 9.8 m/s² × 2 s = 9.8 m

The food package is located 9.8 m vertically below the point where it is dropped

The horizontal position, x, of the package after 2 s is given by the following kinematic equation, x = vₓ × t

Therefore, x = 15.519 m/s × 2 s ≈ 31.038 m

The coordinates of the location of the package 2 seconds after it is dropped is (31.038 m, 9.8 m)

c. The time of flight, [tex]t_{tot}[/tex], of the food package which is the time it takes the package to reach the ground from 125 m, is given as follows;

[tex]t_{tot} = \sqrt{\dfrac{2 \cdot h}{g} } = \sqrt{\dfrac{2 \times 125 \ m}{9.8 \ m/s^2} } \approx 5.051 \ seconds[/tex]

The time of flight of the food package, [tex]t_{125}[/tex] ≈ 5.105 seconds

d. The horizontal distance covered, [tex]x_{tot}[/tex] = vₓ × [tex]t_{tot}[/tex] ≈ 15.519 m/s × 5.105 s = 79.224495 m ≈ 79.22 m.

Answer:

I believe the answer is C

Explanation:

because centripetal force is generally assosiated with rotation and how fast something spins

Torque is the measure of how effectively a force causes rotation because centripetal force is generally assosiated with rotation and how fast something spins.

Torque is a pattern of the force that can make a victim to revolve on an axis. The torque's direction vector based on the force's direction on the axis.

The SI unit of torque is the Newton-meter. The Torque can be both static or dynamic.

A static is one that does not generate an angular acceleration.

The  Torque's magnitude vector ζ for a torque generated by a given force F is;

ζ = F .r sin(θ)

where,

r is the width of the moment arm

θ is the angle within the force vector and the moment arm.

In rotational kinematics, torque is measured as;

ζ = Iα

Where,

α is the angular acceleration

I is the rotational inertia

therefore, Torque is the measure of how effectively a force causes rotation because centripetal force is generally assosiated with rotation and how fast something spins.

Learn more about torque;

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Explanation:

HERE,

momentum =126 kg.m/s

weight =12 kg

we know that,

[tex]\tt{ velocity =\dfrac{momentum }{weight} }[/tex]

According to the question,

Deers velocity

=[tex]\tt{\dfrac{126}{12} }[/tex] ⠀

=[tex]\tt{ 10.5 }[/tex] ⠀

Deers velocity is 10.5 m/s.

Answer:

96500÷5=19300

Explanation:

96500÷5=19300

Answer:

Divide Whole Numbers by Fraction Worksheet

To divide fractions, you need to invert the divisor and multiply. To invert a fraction, reverse the numerator and denominator. The special name given to an inverted fraction is reciprocal. Recall that a whole number has a understood denominator of 1.

Answer:

The moon takes 27 days to revolve around the earth.

Explanation:

I hope this helps :)

The moon takes 27 days to revolve around the Earth.

Answer:radio waves are electromagnetic waves propagating in any non-conductive media by varying the field at each point in it. Sound is a wave of pressure changes of the medium such as air. Radio waves are a combination of electric and magnetic fields that need no medium to travel upon.

Explanation:please give brainliest

Radio waves are longest electromagnetic waves whereas sound waves are mechanical waves. Sound waves can move only through a medium and electromagnetic waves does not need a medium to travel.

Radio waves are a kind of electromagnetic waves. In the electromagnetic spectrum, radio waves has the longest wavelength and smallest frequency. Thus, radio waves have lower energy in comparison to other electromagnetic waves.

Sound waves are mechanical waves. Mechanical waves needs a medium to travel where as electromagnetic waves does not need a medium and they can moves through vacuum.

Sound waves are longitudinal mechanical waves where, the oscillation of particles is in the direction along the wave propagation. Electromagnetic waves are more energetic and faster than sound waves.

To find more on sound waves, refer here:

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 The acceleration of each cart be 4 meter/second².

Acceleration is rate of change of velocity with time. Due to having both direction and magnitude, it is a vector quantity. Si unit of acceleration is meter/second² (m/s²).

Given parameters:

the average force on the 1kg cart is 4N.

Hence, the acceleration of the 1 kg cart be = force/mass

= 4/1 meter/second²

= 4 meter/second².

As two carts are pushed apart by an expanding spring, the acceleration of the other carts also be 4 meter/second².

Learn more about acceleration here:

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Answer:

Here's why this is correct

According to BrightHubEducation, Machines make work easier by changing the size of force, direction of force, or distance the force acts on. Lifting a car with a flat tire and loosening the lug nuts can be accomplished by a single person thanks to simple machines. The jack and lug wrench are simple machines that alter the force needed to change the tire.

Hope this helps!  <3

Answer:

The answer to this question is given below in this explanation section.

Explanation:

"electromagnetic spectrum depends on wavelength and frequency"

When electromagnetic radiation interacts with single atoms and molecule,its behavior also depends on the amount of energy per quantum(photon)it carries wave number =1/wavelength in cm speed of light=wavelength x frequency energy = Planck's constant x frequency.

Electromagnetic radiation interacts with matter in different parts of the spectrum.

Electromagnetic radiation interacts with matter in different ways in different parts of the spectrum.The types of interaction can be so different that it seems justified to refer to different types of radiation.There is a continuum containing all these different kind of electromagnetic radiation.Thus we refer to spectrum but divide it up based on the different interaction with matter.

Answer:

Energy increases with decreasing wavelength and increasing frequency.

Explanation:

Answer:

a. 12.57 m/s b. 39.5 m/s² c. Her centripetal force is four times her weight.

Explanation:

a. What is Missy's linear speed on the rotor?

Missy's linear speed v = 2πr/T where r = radius = 4.0 m and T = time it takes to complete one revolution = 2.0 s

So, v = 2πr/T

= 2π(4.0 m)/2.0 s

= 4π m/s

= 12.57 m/s

b. What is  Missy's centripetal acceleration on the rotor?

Missy's centripetal acceleration, a = v²/r where v = linear velocity = 12.57 m/s and r = radius = 4.0 m

a = v²/r

= (12.57 m/s)²/4.0 m

= 158.01 m²/s² ÷ 4.0 m

= 39.5 m/s²

c. If her mass is 50-Kg, how is the centripetal force  compare to her weight?

Her centripetal force F = ma where m = mass = 50 kg and a = centripetal acceleration = 39.5 m/s².

Her weight W = mg where m = mass = 50 kg and g = acceleration due to gravity = 9.8 m/s².

So, comparing her centripetal force to her weight, we have

F/W = ma/mg

= a/g

= 39.5 m/s² ÷ 9.8 m/s²

= 4.03

≅ 4

So her centripetal force is four times her weight.

Answer:

The answer is density

Explanation:

They density of the air is what makes a difference.

Answer:

The linear speed is 6.51 m/s

Explanation:

Uniform Circular Motion

It's a movement of an object along the circumference of a circle. It can also be defined as a rotation along a circular path.

The angular speed can be calculated as follows:

[tex]\displaystyle \omega=\frac{v}{r}[/tex]

Where:

v = tangential or linear speed

r = radius of the circle described by the rotating object

To calculate the linear speed, solve for v:

[tex]v = \omega\cdot r[/tex]

[tex]v = 21\ rad/s\cdot 0.31\ m[/tex]

[tex]v = 6.51\ m/s[/tex]

The linear speed is 6.51 m/s

Answer:

5 meters

Explanation:

Step one:

given data

mass of the toy car= 50g

Work done= 30J

Force applied F= 5N

Required

The distance moved

Step two:

The expression for the work done is given as

WD= force * distance

substitute

30= 5*d

divide both sides by 5

d=30/5

d= 5m

The distance moved is 5 meters

Answer:

21 miles

Explanation:

3 miles an hour for 7 hours

Its simply 7m*3m/hr=21 miles

Answer:

Electromagnet.

Explanation:

Electric bulb and electric water heather are application of heating effect of electric current. The electromagnet is not the result of heating effect of electric current. The bulb gives light due to the heating effect similarly the water is heated or warmed by the heating effect of electric current.

Answer:

It will take George 20 minutes to get to his friends house.

Explanation:

divide 5km by 15km and get a constant of 3

George is riding at 15KM/HR meaning divide the hour by 3

60 minutes by 3 is 20

Answer:

6.25 m/s.

Explanation:

Total distance travelled = 100 m

Total time = 16 s

Average speed =?

Average speed is simply defined as the ratio of total distance travelled to the total time taken to cover the distance. Mathematically, it is expressed as:

Average speed = total distance / total time

With the above formula, we can obtain the average speed of Sonny Toomey as illustrated below:

Total distance travelled = 100 m

Total time = 16 s

Average speed =?

Average speed = total distance / total time

Average speed = 100 / 16

Average speed = 6.25 m/s

Therefore, the average speed of Sonny Toomey is 6.25 m/s

Answer:

m/s^2, acceleration

Explanation:

velocity in SI units is meter / second

dividing by time(second) gives meter / second^2 which is acceleration.

Answer: D.Touch it with the ground

Explanation:

The charged object can become neutral if touched with the ground in a process known as grounding.

If the charged object is negatively charged, excess electrons will flow into the ground thus making the object neutral. If the object is positively charged, electrons will flow from the ground into the object and neutralise it.

Answer:

120

Explanation:

10 x 3 = 30

30 x 4 = 120

I hope this helps u! :D

Answer: ayee fanks bro

Explanation:

Answer:

36 N

Explanation:

The tension on the string :

T =mv²/r ------where

m= mass of object = 8 kg

v= tangential velocity = 3 m/s

r= length of the string = 2m

T= [ 8 * 3² ] / 2

T= 36 N

Given :

A 13.3 kg box sliding across the ground  decelerates at 2.42 m/s².

To Find :

The coefficient of kinetic friction.

Solution :

Frictional force applied to the box is :

[tex]f = ma[/tex]    ....1)

Also, force of friction is given by :

[tex]f = \mu mg[/tex]  ....2)

Equating equation 1) and 2), we get :

[tex]\mu mg = ma\\\\\mu = \dfrac{a}{g}\\\\\mu = \dfrac{2.42}{9.8}\\\\\mu = 0.247[/tex]

Therefore, the coefficient of kinetic friction is 0.247 .

Answer:

An unbalanced force can change an object's motion. An unbalanced force acting on a still object could make the object start moving. An unbalanced force acting on a moving object could make the object change direction, change speed, or stop moving.

Answer:

17N right

Explanation:

Answer:

pressure=force/area

p=600/50

p=12

so 12Nm^-1

Answer: candela

Explanation:

The SI unit for the measurement of intensity is referred to as the candela. The candela is simply used in the measurement of the visual intensity with regards to light sources such as the bulb we have in torches or the light bulbs that we have in our various homes. It is the power that a light source emits in a certain direction.