A weed eater does 21 kJ of work in 0.750 h. What power does it develop?
Answer:
[tex]p = \frac{w}{t} [/tex]
21kj÷0.750
28w
5. A cable is attached 32.0 m from the base of a flagpole that is about to
be raised. The raising of the pole is temporarily halted when the pole is
at an angle of 60.0° with respect to the ground. If the cable exerts a ver-
tical force of 1.233 x 104 N downward and a horizontal force of 1.233 x
104 N to the left, what is the length of the flagpole?
Answer:
The length of the flagpole is approximately 87.43 m
Explanation:
The given parameters of the cable attached to the flagpole are;
The point along the flagpole at which the cable is attached = 32.0 m
The angle with respect to the ground at which the raising of the flagpole is halted = 60.0°
The downward force exerted by the cable, [tex]F_v[/tex] = 1.233 × 10⁴ N
The force exerted by the cable to the left = 1.233 × 10⁴ N
Let 'W' represent the weight of the flagpole, at equilibrium, we have;
The sum of vertical forces = 0
Therefore;
[tex]F_v[/tex] + W - R = 0
W - R = -1.233 × 10⁴ N
Taking moment about the support at the base of the pole, we get;
1.233 × 10⁴ × d × cos(60.0°) - 1.233 × 10⁴ ×d× sin(60.0°) + W × d/2 ×cos(60.0°) = 0
∴ W × d/2 ×cos(60.0°) ≈ 4513.093·d
W = 2 × 4513.093/(cos(60.0°)) ≈ 18,052.373 N
R = 18,052.373 + 1.233 × 10⁴ ≈ 30,382.373
R ≈ 30,382.373 N
Taking moment about the point of attachment of the cable to the ground, we have;
W × ((d/2) × cos(60.0°) + 32) = R × 32
∴ (d/2) = ((30,382.373 × 32/18,052.373) - 32)/(cos(60.0°)) ≈ 43.71281
d = 2 × 43.71281 ≈ 87.43
The length of the flagpole, d ≈ 87.43 m
Which physical property is defined as the amount of space that matter occupies?
Answer:
The matter has mass and takes up space. The amount of space that matter takes up is called its : density
Answer:
Mass
Explanation:
Mass is the amount of matter occupied by an object.
A disk 7.90 cm in radius rotates at a constant rate of 1 190 rev/min about its central axis. (a) Determine its angular speed. 124.58 Correct: Your answer is correct. rad/s (b) Determine the tangential speed at a point 2.98 cm from its center. 3.71 Correct: Your answer is correct. m/s (c) Determine the radial acceleration of a point on the rim. magnitude 1.23 Correct: Your answer is correct. km/s2 direction toward the center Correct: Your answer is correct. (d) Determine the total distance a point on the rim moves in 2.06 s. 20.28 Correct: Your answer is correct. m
Answer:
[tex]124.62\ \text{rad/s}[/tex]
[tex]3.71\ \text{m/s}[/tex]
[tex]1.23\ \text{km/s}^2[/tex]
[tex]20.28\ \text{m}[/tex]
Explanation:
r = Radius of disk = 7.9 cm
N = Number of revolution per minute = 1190 rev/minute
Angular speed is given by
[tex]\omega=N\dfrac{2\pi}{60}\\\Rightarrow \omega=1190\times \dfrac{2\pi}{60}\\\Rightarrow \omega=124.62\ \text{rad/s}[/tex]
The angular speed is [tex]124.62\ \text{rad/s}[/tex]
r = 2.98 cm
Tangential speed is given by
[tex]v=r\omega\\\Rightarrow v=2.98\times 10^{-2}\times 124.62\\\Rightarrow v=3.71\ \text{m/s}[/tex]
Tangential speed at the required point is [tex]3.71\ \text{m/s}[/tex]
Radial acceleration is given by
[tex]a=\omega^2r\\\Rightarrow a=124.62^2\times 7.9\times 10^{-2}\\\Rightarrow a=1226.88\approx 1.23\ \text{km/s}^2[/tex]
The radial acceleration is [tex]1.23\ \text{km/s}^2[/tex].
t = Time = 2.06 s
Distance traveled is given by
[tex]d=vt\\\Rightarrow d=\omega rt\\\Rightarrow d=124.62\times 7.9\times 10^{-2}\times 2.06\\\Rightarrow d=20.28\ \text{m}[/tex]
The total distance a point on the rim moves in the required time is [tex]20.28\ \text{m}[/tex].
10. How much total work do you do when you lift a 50 kg microwave 1.0 m off the ground and then push it 1.0 m
across a counter with a force of 50 N?
Work formula:
[tex]W = Fd\cos(\theta)[/tex]
F = 50N, d = 1.0 m
When you lift something straight up, the angle of the force is 90º
cos(90º) is 0, so there's no work done when you lift the microwave off the ground
[tex]W = (50N)(1.0)(0) = 0[/tex]
F = 50N, d = 1.0 m
When you push the microwave, the angle is 0º and cos(0º) is 1. So there is work done here:
[tex]W = (50 N)(1.0m)(1)[/tex]
[tex]W = 50[/tex]
total work = 50 joules
Explain why it is impossible to have a temperature value less than 0 K.
Answer is in the photo. I can only upload it to a file hosting service. link below!
tinyurl.com/wpazsebu
Answer:
0 Kelvin is equal to -459.67 Fahrenheit which is also absolute zero. Along with that at zero Kelvin or minus 273 degrees Celsius or minus 459.67 Fahrenheit the particles stop moving and all disorder disappears. Thus, nothing can be colder than absolute zero on the Kelvin scale. Luckily 0 Kelvin is believed to be impossible to reach with our current technology.
-BlueBoy
Question 1 and 2 and 3 physics lesson homework
Answer:
Jackson 2: Smart 3: Ahmed
Explanation:
square + circle = egg
oops, wrong guy
What sport was invented by the English?
Answer:Cricket !
The origins of cricket are very vague, and many theories have been put forward suggesting its origins, but it is, without doubt, very English. The first evidence of cricket being played was recorded in the year 1550, by the pupils of Royal Grammar School, Guildford.
Hope this helps ! ✨What does it take to change the direction or speed of an object
Answer:
An object's speed or direction can be changed by a force. This means a greater force against a lesser force, and it results in acceleration. This means any push or pull against another equal push or pull. It results in no change of acceleration
Explanation:
PLS ANSWERR THIS QUESTION FOR ME !!
Explanation:
20 joule is your answer
Answer:
here
mass m =100kg
distance d=50m
acceleration due to gravity a =10m/s²
work =force×displacement
= ma/d=100×10/50=20joule
How bones do humans have ??
Answer:
206
Explanation:
The axial skeleton, comprising the spine, chest and head, contains 80 bones. The appendicular skeleton, comprising the arms and legs, including the shoulder and pelvic girdles, contains 126 bones, bringing the total for the entire skeleton to 206 bones.
A fully grown adult features 26 bones in the spine, whereas a child can have 34.
Answer:
The human body is made up of 206 bones
Which statement correctly describes the relationship between air temperature and air pressure?
-Warm air rises, creating an area of low pressure.
-Cool air sinks, creating an area of low pressure.
-Warm air sinks, creating an area of low pressure.
-Cool air rises, creating an area of low pressure.
What is the amount of work required to increase a 1100 kg car's speed from 20.0 m/s to 30.0 m/s?
Answer:
250,000 im not really sure about this answer but this is what I got
The amount of work required to increase the speed of the car is 275000 J.
To calculate the amount of work required to increase the speed of the car, we use the formula below.
Formula:
W = m(v²-u²)/2................ Equation 1Where:
W = amount of work needed to increase the speed of the carm = mass of the caru = initial speed of the carv = final speed of the car.
From the question,
Given:
m = 1100 kgu = 20 m/sv = 30 m/sSubstitute these values into equation 1
W = 1100(30²-20²)/2W = 1100(900-400)/2W = 1100(500)/2W = 1100×500/2W = 275000 JHence, The amount of work required to increase the speed of the car is 275000 J.
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The gravitational force between two bodies is 250N . What will the new force be if one of the masses is tripled?
If one of the masses is tripled, then their product is tripled, and the force between them is tripled. The new force is 750N .
Doubling the loudness of a sound wave requires the intensity to
by a factor of
A) increase, two
B)
decrease, two
C
increase, ten
D
decrease, ten
Answer: C. Increase, ten
Explanation: A doubling of the sensed volume (loudness) is equivalent to a level change approximately between 6 dB and 10 dB.
You throw a basketball from a cliff to the ground. The ball has an initial velocity of 12 m/s in the horizontal direction. After 3.0 seconds, the ball has a velocity of -30.0 m/s in the y-direction.
What is the direction of motion of the ball at time t= 3.0 s? (Hint: direction is related to the angle).
Answer:
The direction of motion of the ball is approximately 68.199º below the +x semiaxis.
Explanation:
The ball has a two-dimension motion, to be exact, a parabolical motion, that is, a motion at constant velocity in the x-direction and free fall motion in the y-motion. Hence, the horizontal velocity of the basketball is 12 meters per second and its direction ([tex]\theta[/tex]), in sexagesimal degrees, is calculated by this trigonometrical expression:
[tex]\theta = \tan^{-1} \frac{v_{y}}{v_{x}}[/tex] (1)
Where:
[tex]v_{x}[/tex] - Horizontal velocity, in meters per second.
[tex]v_{y}[/tex] - Vertical velocity, in meters per second.
If we know that [tex]v_{x} = 12\,\frac{m}{s}[/tex] and [tex]v_{y} = -30\,\frac{m}{s}[/tex], then the direction of motion of the ball is:
[tex]\theta \approx 68.199^{\circ}[/tex] (below the +x semiaxis)
The direction of motion of the ball is approximately 68.199º below the +x semiaxis.
In a ride in an amusement park, a carriage of mass 450 kg is travelling horizontally at a speed of 18 m/s. It passes through a shallow tank containing stationary water. The tank is of length 9.3 m. The carriage leaves the tank at a speed of 13 m/s. PT 3 a.) Calculate the change in kinetic energy of the cart while it passes through the water tank J (Hint: Change
Answer:
98.
Explanation:
divide
The change in the kinetic energy of the cart is equal to 34875 J.
What is kinetic energy?The energy which is possessed by a moving body because of its motion is known as kinetic energy. Work should be done in order to bring the change in the kinetic energy of a moving object.
The kinetic energy of a moving object can be determined from the formula mentioned below:
K.E. = ½mv² where ‘m’ and 'v' is the mass and velocity of the object.
Given, the mass of the carriage, m = 450 Kg
The speed of the carriage, u = 18 m/s
The initial kinetic energy of the cart = (1/2) × 450 × (18)²
(K.E.)₁ = 72900 J
The final speed of the cart, v = 13 m/s
The final kinetic energy of of the cart = (1/2) × 450 × (13)²
(K.E.)₂ = 38025 J
The change in the kinetic energy of the cart = (K.E.)₂ - (K.E.)₁
Change in the kinetic energy = 72900 - 38025 = 34875 J
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What should food workers do to prevent chemical hazards from contaminating food?
A. Wash their hands after taking out the garbage
B. Wear a hair net when working for food preparation areas
C. Store cleaning solutions and bottles away from food storage areas
D. Clean and San at is equipment and utensils for after hours of continuous use
Q7) A box sliding with a velocity of 5 m/s accelerates at 2 m/s^2. How
much is the box displacement after 6 s?
Answer:
The box displacement after 6 seconds is 66 meters.
Explanation:
Let suppose that velocity given in statement represents the initial velocity of the box and, likewise, the box accelerates at constant rate. Then, the displacement of the object ([tex]\Delta s[/tex]), in meters, can be determined by the following expression:
[tex]\Delta s = v_{o}\cdot t+\frac{1}{2}\cdot a\cdot t^{2}[/tex] (1)
Where:
[tex]v_{o}[/tex] - Initial velocity, in meters per second.
[tex]t[/tex] - Time, in seconds.
[tex]a[/tex] - Acceleration, in meters per square second.
If we know that [tex]v_{o} = 5\,\frac{m}{s}[/tex], [tex]t = 6\,s[/tex] and [tex]a = 2\,\frac{m}{s^{2}}[/tex], then the box displacement after 6 seconds is:
[tex]\Delta s = 66\,m[/tex]
The box displacement after 6 seconds is 66 meters.
A silver tea spoon is placed in a cup filled with hot tea. After some time, the exposed end of the spoon becomes hot even without a
direct contact with the liquid. This phenomenon can be explained by:
Answer:
As atoms in the spoon vibrates about their equilibrium positions and transfer energy form one end to other end. This process is called conduction.
Compare the concepts of mass and weight. Name three differences.
Answer:
1a)Mass is the amount of matter in the body.
1b)Weight is the measure of the amount of force acting on a mass due to acceleration and gravity.
2a)Mass can never be zero
2b)Weight can be zero if no gravity acts upon an object. like in space
3a) Mass does not change according to location.
3b)Weight varies according to location.
Calculate the amount of heat needed to convert 0.8 kg of ice at -19 °C into water at 29 °C.
5. In which image below is the most work being wasted as heat?
A. Image A
B. Image B
C. Image C
D. Image d
Answer:
C
Explanation:
The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
What will be the speed of the rock?Initial speed of the rock, u = 40m/s
Final position of the rock s = 0m taking the release point as reference. The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
Nuclear energy is a useful source of power but has disadvantages. The disadvantage of nuclear energy is it produces dangerous waste.
Initial speed of the rock, u = 40m/s
Final position of the rock s = 0m taking the release point as reference
From the second equation of motion:
solving above we get:
t = 0s or t = 8.16s, t =0 seconds is neglected since it represents the initial position which is the same as the final position at t = 8.16s
So, the rock takes 8.16 seconds to return to the release point.
Therefore, The rock takes 8.16s to return to its release point. Given that the elastic band provides a speed of 40m/s to the rock in 10 cm stretch.
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When heat is added to ice, the first change it goes through will be which of the following?
It will begin to boil.
It will melt into a liquid.
It will turn into steam.
It will become a vapor.
Answer:
it will begin to melt into a liquid
Explanation:the ice will melt first before turning into a liquid.
what is vector product B×A of two vectors A=7i+4j-8k and B=3i-3j+5k
Answer:
[tex]4i+59j+33k[/tex]
Explanation:
Given that,
Vector A = 7i+4j-8k
vector B = 3i-3j+5k
We need to find B×A. It can be calculated as follows :
[tex]B\times A=(3i-3j+5k)\times (7i+4j-8k)\\\\=i (24 - 20) - j (-24 - 35) + k (12 + 21) \\\\=4i+59j+33k[/tex]
So, the value of vector product is [tex]4i+59j+33k[/tex].
What is the correct answer! Thank you for your help
What is the velocity of a wave with a frequency of 45 Hertz and a wavelength of 3 meters?
Explanation:
By using v=( f )x( lambda )
v= 45 s^-1 x 3 m
Therefore v = 135 ms^-1
Suppose to a scientist was able to construct a barometer with a liquid being twice denser than mercury, then how would the liquid raise at standard pressure?
Answer:
h = h₀/2, the liquid column rises half the height
Explanation:
Pressure is defined as force per area,
P = F / A
in a barometer the force is the weights of the liquid column
F = W = mg
P = m g/A
if we use the definition of density
ρ = [tex]\frac{m}{A h}[/tex]
[tex]\frac{m}{A}[/tex] = ρ h
we substitute
P = ρ g h
Let's use the index o for the mercury
P₀ = ρ₀ g h₀
when we change the liquid for another with
ρ = 2ρ₀
the pressure expression is
P = 2ρ₀ g h
in the problem they indicate that the pressure is equal to the initial P = P₀
we substitute
ρ₀ g h₀ = 2ρ₀ g h
h₀ = 2h
h = h₀/2
the liquid column rises half the height
A student conducts an experiment in which a cart is pulled by a variable applied force during a 2 s time interval. In trial 1, the student exerts the force on a cart of mass M. In trial 2, the student exerts the force on a cart of mass 3M. In trial 3, the student exerts the force on a cart of 5M. In which trial will the cart experience the greatest change in momentum from 0 s to 2 s?
Answer:
The answer is "Including all three studies of 0s to 2s, that shift in momentum is equal".
Explanation:
Its shift in momentum doesn't really depend on the magnitude of its cars since the forces or time are similar throughout all vehicles.
Let's look at the speed of the car
[tex]F = m a\\\\a =\frac{F}{m}[/tex]
We use movies and find lips
[tex]\to v = v_0 + a t\\\\\to v = v_0 + (\frac{F}{m}) t[/tex]
The moment is defined by
[tex]\to p = m v[/tex]
The moment change
[tex]\Delta p = m v - m v_0[/tex]
Let's replace the speeds in this equation
[tex]\Delta p = m (v_0 + \frac{F}{m t}) - m v_0\\\\\Delta p = m v_0 + F t - m v_0\\\\\Delta p = F t[/tex]
They see that shift is not directly proportional to the mass of cars since the force and time were the same across all cars.
An object's speed is 0.8 m/s, and its momentum is 200 kg-m/s What is the mass of the object?
A. 250kg
B. 200kg
C.160kg
D.128kg
Answer:
A: The mass would be 250kg
Explanation:
In terms of an equation, the momentum of an object is equal to the mass of the object times the velocity of the object. where m is the mass and v is the velocity. The equation illustrates that momentum is directly proportional to an object's mass and directly proportional to the object's velocity.
p= mv
m= p/ v
The explanation to that is:
momentum = mass× velocity
mass= momentum / velocity
THE ANSWER IS A
Hope this helps!