a crane lifts a 75 kg mass at a height of 8m . calculate the gravitational potential energy gained by the mass (g= 10N)
1- If a skater travels 50 miles in one hour, what is the skaters speed?
2- A biker travels 10 miles in two hours, what is his speed?
3- A driver is going 42 miles in a 15 mph school zone and is pulled over by a police officer. The speed the driver was driver is known as what type of speed?
Which two options describe physical properties of matter?
Answer:
A and B
Explanation:
A.P.E.X
Currents exist in the ocean without the need of electric fields.
True
False
Answer:
True
Explanation:
5. Graph A below plots a race car's speed for 5 seconds. The car's rate of acceleration is 6 m/s^2
6. Graph B below plots the same car's speed for a different
5-second interval. The car's acceleration during this interval is 12 m/s^2
Answer:
The answer is below
Explanation:
We are to check if the statement is true of false. If it is false, we correct the statement.
Solution:
Acceleration is the time rate of change of velocity. It is the ratio of the change in velocity to the change in time. The acceleration can be gotten from a velocity time graph by finding the slope of the graph.
The x coordinate represent the time and the y coordinate velocity.
5) Graph A passes through the point (0, 0) and (4, 24). Therefore the acceleration (slope) is:
Acceleration = [tex]\frac{24-0}{4-0}=6\ m/s^2[/tex]
This is correct.
6) Graph B is a straight line of 12 m/s. It passes through (0, 12) and (4, 12). Hence:
Acceleration = [tex]\frac{12-12}{4-0}=0\ m/s^2[/tex]
This is false.
Therefore the acceleration of graph B is 0 m/s².
Is water a element or compound
Answer:
compound
Explanation:
water is made up of oxygen (O) and hydrogen (H) therefore making it a compound (H2O)
How/is climate change/human interaction affecting mutualism
Calculate the magnetic field at 2m from a straight wire carrying a current of 5 A. (K = 2 x 10 ^-7)
Answer:
[tex]B=5\times 10^{-7}\ T[/tex]
Explanation:
Given that,
Current in a wire, I = 5 A
We need to find the magnetic field at 2m from a straight wire carrying a current of 5 A.
The magnetic field due to a wire is given by :
[tex]B=\dfrac{\mu_0I}{2\pi r}\\\\B=\dfrac{4\pi \times 10^{-7}\times 5}{2\pi \times 2}\\\\B=5\times 10^{-7}\ T[/tex]
So, the required magnetic field is [tex]5\times 10^{-7}\ T[/tex].
Mass of 23.94kg and volume 2.10 cubic centimeters. Calculate the density of the copper wire in si units (ų/mm cubic)
Answer:
Density = 1.14 kg/mm³
Explanation:
Given the following data;
Volume = 2.10 cm³ to mm = 2.10 * 10 = 21 mm³
Mass = 23.94kg
To find the density;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
Substituting into the equation, we have;
[tex]Density = \frac{23.94}{21}[/tex]
Density = 1.14 kg/mm³
if the mass of the object is doubled and the speed is halved then kinetic energy will change by a factor of:
2
4
1/2
1/4
Answer:
kinetic energy will change by a factor of 1/2
Option C) 1/2 is the correct answer
Explanation:
Given the data in the question;
we know that;
Kinetic energy = 1/2.mv²
given that mass of the object is doubled; m1 = 2m
speed is halved; v1 = V/2
Now, New kinetic energy will be; 1/2.m1v1²
we substitute
Kinetic Energy = 1/2 × 2m × (v/2)²
Kinetic Energy = 1/2 × 2m × (v²/4)
Kinetic Energy = 1/2 × m × (v²/2)
Kinetic Energy = 1/2 [ 1/2mv² ]
Kinetic Energy = 1/2 [ KE ]
Therefore; kinetic energy will change by a factor of 1/2
Option C) 1/2 is the correct answer
I can give you 50 points.
Freddy is participating in a pumpkin lifting contest. The 68 kg pumpkin starts at rest on the ground. If Freddy exerts a 720N force on the pumpkin, what is the acceleration of the pumpkin as he lifts it off the ground?
Draw a Force Diagram for the pumpkin. Indicate the direction of the sum of the forces.
Draw a Motion Diagram for the pumpkin. Is your motion diagram consistent with your force diagram?
Use Newton’s 2nd Law to find the pumpkin’s acceleration.
Answer:
Freddy is participating in a pumpkin lifting contest. The 68 kg pumpkin starts at rest on the ground. If Freddy exerts a 720N force on the pumpkin, what is the acceleration of the pumpkin as he lifts it off the ground?
Explanation:
When designing structures, it is important to know the physical properties of your construction materials, and the forces that will be exerted on those materials after construction is complete.
a. True
b. False
Answer:
a. True
Explanation:
This statement is true, and incredibly important. Every material used in construction has a breaking point and a deformation point. A breaking point is the amount of stress or weight material can handle before it completely gives out and breaks while the deformation point is the point in which it begins to bend or change its shape. Therefore, it is incredibly important to know both this information and the amount of force that will be exerted onto the materials. Mainly because if the amount of force exceeds these points it will cause the material to deform/break which can cause the entire structure to collapse and either injure or kill many people.
state the number of significant figures in 0.00245
Sound travels on air molecules.
True
False
Answer:
I think the answer is true.
Explanation:
how does changing the distance between two objects affect the gravitational force between them? what about changing their masses
Answer:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects
help please
the question is in the picture
Answer:
The SI unit of power is the watt
Explanation:
) The radius of sphere measured repeated values 5.63 m, 5.54 m and 5.53 m. Determine the most
probable value of radius.
Answer:
v_{ average} = 5.57
Explanation:
The most probable value of a measure is
v_average = [tex]\frac{1}{N}[/tex] ∑ x_i
where N is the number of measurements
in tes case N = 3
v_{average} = ⅓ (5.63 +5.54 + 5.53)
V_{average} = 5,567
The number of significant figures must be equal to the number of figures that have the least in the readings.
v_{ average} = 5.57
radiation with shorter wavelengths has higher energy. the diagram below illustrates the relationship of wavelength and frequency. which of these correctly shows types of radiation increasing in energy?
Answer:
wavelength of light and dark and light and dark brown
WILL MARK BRAINLIEST IF CORRECT. WILL GIVE 30 POINTS. PLEASE ANSWER
A construction company plans to set up business in a specific location near a river. In your own words, explain the potential impacts on the economy, environment, and water cycle.
Answer:
it increases economical level .water will be polluted.water cycle do not take place nicely.it causes global warming and acid rainfall
Sam, whose mass is 78 kg , stands at the top of a 11-m-high, 110-m-long snow-covered slope. His skis have a coefficient of kinetic friction on snow of 0.07. If he uses his poles to get started, then glides down, what is his speed at the bottom
Answer:
v = 8.09 m/s
Explanation:
For this exercise we use that the work done by the friction force plus the potential energy equals the change in the body's energy.
Let's calculate the energy
starting point. Higher
Em₀ = U = m gh
final point. To go down the slope
Em_f = K = ½ m v²
The work of the friction force is
W = fr L cos 180
to find the friction force let's use Newton's second law
Axis y
N - W_y = 0
N = W_y
X axis
Wₓ - fr = ma
let's use trigonometry
sin θ = y / L
sin θ = 11/110 = 0.1
θ = sin⁻¹ 0.1
θ = 5.74º
sin 5.74 = Wₓ / W
cos 5.74 = W_y / W
Wₓ = W sin 5.74
W_y = W cos 5.74
the formula for the friction force is
fr = μ N
fr = μ W cos θ
Work is friction force is
W_fr = - μ W L cos θ
Let's use the relationship of work with energy
W + ΔU = ΔK
-μ mg L cos 5.74 + (mgh - 0) = 0 - ½ m v²
v² = - 2 μ g L cos 5.74 +2 (gh)
v² = 2gh - 2 μ gL cos 5.74
let's calculate
v² = 2 9.8 11 - 2 0.07 9.8 110 cos 5.74
v² = 215.6 -150.16
v = √65.44
v = 8.09 m/s
2. Fill in the blanks
a. Two bodies are rubbed against each other they acquire __________and _____________
charges.
b. ___________are transferred from one object to another when two objects are charged by
friction.
c. __________ is a device used to secure tall buildings from the effect of lightning
d. __________charge is obtained by plastic comb when rubbed with dry hair.
e. Lightning is __________ on huge scale
Answer:
a. Two bodies are rubbed against each other they acquire equal and Opposite charge.
b. Electron are transferred from one object to another when two objects are charged by friction.
c. Lightening rod is a device used to secure tall buildings from the effect of lightning
d. Negative charge is obtained by plastic comb when rubbed with dry hair.
e. Lightning is natural spark discharge on huge scale.
Hope this helps you. Do mark me as brainliest.
Imagine that you have three circuit elements: a single bulb, a piece of wire, and a battery. You start by keeping these three elements separate and unconnected. You use a voltmeter to measure the voltage across each of the three elements. Then, you connect the bulb, wire, and battery together to form a complete circuit, so that the bulb lights up. You repeat the measurements you made before, using the voltmeter to measure the voltage across each element while it is in the complete circuit. For the questions below, assume that the battery and the wire are ideal.
a. Compare the voltage across the battery: a) when the battery is by itself vs b) when the battery is part of the complete circuit. Is the voltage across the battery different in these two situations, or is the voltage the same? Explain your answer.
b. Compare the voltage across the bulb: a) when the bulb is by itself vs b) when the bulb is part of the complete circuit. Is the voltage across the bulb different in these two situations, or is it the same? Explain.
c. Now compare the voltage across the piece of wire: a) when the wire is by itself vs b) when the wire is part of the complete circuit. Is the voltage across the piece of wire different in these two situations, or is it the same? Explain your answer.
d. Now consider only the situation in which the battery, wire, and bulb have been arranged to form a complete circuit in which the bulb lights up. For this situation, rank i) the voltage across the battery, ii) the voltage across the bulb, and iii) the voltage across the piece of wire, according to their absolute values, from greatest to smallest. If any are the same, or if any are zero, state that explicitly. Explain your reasoning.
Answer:
A) two voltages are equal, B) the two voltages are different
C) voltage is the same V = 0, D) V_{battery} = V_{Lamp} > V_{wire}
Explanation:
For this exercise, it is asked to build a circuit with the plug, the lamp and the battery, the circuit must be a series circuit
Before connecting the battery voltage is Vo as they indicate that it is ideal there are no losses, the voltages of the other elements are zero.
A) Voltages battery
a) single battery Vo
b) the battery is connected to the lamp this takes something current, but the electromotive force does not change therefore the voltage is Vo; This is because the battery's energy comes from a chemical reaction of the elements inside it.
in summary the two voltages are equal
B) voltage Lamp
a) when the bulb is single, its voltage is zero V = 0
since it has no energy
b) when in the circuit V = V₀ - V_r
where V_r is the voltage across the wire, due to its resistance, the energy for these voltages is given by the battery
in this case the two voltages are different
C) the voltage across the wire
a) unconnected V = 0
b) connected V = V₀ - V_L
where V_L is the voltage across the lamp due to its resistance
we can write the wire voltage
V_r = i R
as they indicate that the wire is ideal, its resistance is zero R = 0, consequently
V_r = 0
the voltage is the same V = 0
D) circuit voltage
For this part we must write Ohm's law for this circuit
V₀ = V_L + V_r
where V₀ is the battery voltage, V_L and V_r are the voltage of the lamp and the wire, respectively.
The voltage of each element is
V_L = i R_L
V_r = i R
This is a series circuit so the current is also constant
V₀ = i (R_L + R)
therefore the voltage in the battery is the highest V₀
the voltage across the wire if it is ideal is zero V_r = 0, if it is ideal its resistance is zero
therefore the voltage on the lamp is equal to the voltage of the battery
V_{battery} = V_{Lamp} > V_{wire}
Explain how heat is related to temperature and thermal energy...
PLEASE NO COPY AND PASTE DO IT IN YOUR OWN WORDS
PLEASEEEE HELP MEEEE!!
Answer:
Thermal energy is directly related to heat because thermal energy is how heat is transfered.
Engineers and science fiction writers have proposed designing space stations in the shape of a rotating wheel or ring, which would allow astronauts to experience a sort of artificial gravity when walking along the inner wall of the station's outer rim. (a) Imagine one such station with a diameter of 117 m, where the apparent gravity is 3.10 m/s2 at the outer rim. How fast is the station rotating in revolutions per minute
Answer:
Explanation:
The apparent gravity decreases because of centrifugal force that is acting on the astronaut .
centrifugal acceleration = ω²r , ω is angular velocity and r is radius of circular path .
Given
r = 117/2 = 58.5 m .
centrifugal acceleration = (2πn)²r , where n is revolution per minute.
= 4 π² n² r
Given g - 4 π² n² r = 3.10
9.8 - 39.43 x n² x 58.5 = 3.10
6.7 = 2306.65 n²
n² = .0029
n = .05385 rev /s
= 3.23 rev per minute .
A brown bear runs at a speed of 9.0 m/s with 23, 000 J of kinetic energy.
What is the bear's mass?
Round answer to two significant digits.
Please help!
Answer:
mass = 0.5679 Kg
hope this helps!
which of the following can cause skin cancer and which can't?
Campfire
Flashlight
Lamp
Sun
Tanning bed
fluorescent light bulbs
A hot piece of copper is placed in water in an insulated cup. What is the final
temperature of the water and copper?
(Use
me AT: + copperfcoppe, Acoppe: = 0]
m = 0.50 kg water = 4.18 kJ/kg-'c,
m.copper = 0.50 kg, Cropper = 0.386 kJ/kg-°C, Ti copper = 115°C
Tower = 22°C
O A. 30°C
B. 45°C
O C. 39°C
O D. 52°C
Answer:
38.7 °C.
The final temperature (reached by both copper and water) is 38.7 °C.
So the answer is probably C.
The heat energy lost by the metal piece is equal to the heat gained by the water in the cup. From this concept using calorimetric equation, their final temperature is equal to 30°C.
What is calorimetric equation?Calorimetric equation states the relation between heat energy absorbed or released by a system with the mass, specific heat capacity and temperature difference of the matter as written below:
q = m c Δ
Given, mass of copper piece = 0.50 kg
mass of water = 0.50 kg
c for Cu = 0.386 KJ/Kg °C
c for water = 0.418 KJ/Kg °C
The heat energy lost by copper metal is equal to the heat energy gained by water. Let T be the final temperature.
then,
0.50 kg × 0.386 KJ/Kg °C × (115°C - T) = 0.50 kg × 0.418 KJ/Kg °C × (T - 22°C).
2.09 (115°C - T) = 0.193 (T - 22°C).
2.09 T - 45.98 + 0.193 = 22.195
T = 30°C
Therefore, the final temperature of water and copper piece is 30 °C.
Find more on calorimetry:
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HELP!! ILL GIVE BRAINLIEST As we've learned so far, the popular model of the solar system shifted over
time from geocentric (or Earth centered) to heliocentric (or sun centered).
What role do you think technology played in this shift?
What types of astronomical tools not available to early scientists who
supported the geocentric view helped thinkers in the 16th century and beyond
develop the heliocentric model?
Answer:
geotric earth simulator I think ya I have no idea
Help plzzzzzz
A ball at the end of a sting is being swung around a circle at a constant speed of 1 revolution per second. Why is the ball accelerating?
Answer:
Since the ball is moving with a constant speed S therefore its tangential acceleration is zero direction. Now as the ball is in a circular path so it has centripetal force which is always toward the center of circular pathos the ball and perpendicular to the velocity which is along the tangent on the circle at any point. Therfore net force is always perpendicular to the velocity vector and at all points and always pointed inward.
Explanation:
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the focal length of a concave mirror is 15cm. Calculate the image distance if an object is placed at the center of curvature
Answer:
-15
Explanation: