An Olympic skier glides down a hill, inclined at 25° to the horizontal, at 18 m/s.
How long did it take for her to ski 800 m to the bottom of the hill?
44.4 s
10.5 s
4.0 s
1.6 s
Divide total meters by meters per second:
800 m / 18 m/s = 44.4 seconds
Answer: 44.4
Given the force diagram of the basketball, what can you tell about the basketball motion?
Newton's laws allow to find the result for the movement of the basketballl:
On the vertical axis the ball is on the ground. On the horizontal axis the ball is accelerating in the direction of the pushing force.
Newton's laws establish the relationship between the forces on objects:
The 1st law states that if the net force is zero the object is stationary or with constant speed. The 2nd law gives a relation of the force with the mass and the acceleration of the body. The 3rd. Law states that the force appears in pairs, one on each body with the same magnitude, but in the opposite direction.
Let's apply these principles to the ball's motion diagram.
The two vertical forces are in the opposite direction, one is due to the weight of the body and the other is the attraction of the earth to the support of the ball, they are of equal magnitude, not their action-reaction force and reluctant because it is applied to the same body
In conclusion we can say that the ball is on the ground.
The two horizontal forces are in the opposite direction, the thrust force is greater than the friction therefore using Newton's second law the ball must be accelerating in the direction of the thrust force.
In conclusion we can say that the ball is accelerating in the direction of the pushing force.
In conclusion using Newton's laws we can find the result for the motion of the basketball:
On the vertical axis the ball is on the ground. On the horizontal axis the ball is accelerating in the direction of the pushing force.
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If work stays the same and the distance is increased, then less force is needed to do the work.
True
False
Answer:
False
Explanation:
This is because the work is the same so the force won't change
determine the total current on the circuit bellow
Answer:
170/179 A ≈ 949.7 mA
Explanation:
Finding equivalent impedance of a bridge network can be simplified by converting one end of it from a Δ to a Y configuration. The equivalent resistance in the Y connection is the product of the two resistors connected to that node, divided by the sum of all three resistors.
Considering the left side of the top two branches, the equivalent Y network values are ...
(10)(15)/(10+15+25) = 150/50 = 3 . . . ohms
connected to the right-end node
(25)(10)/50 = 5 . . . ohms
connected to the top-center node, and ...
(25)(15)/50 = 7.5 . . . ohms
connected to the center node of the middle branch.
__
Then the top two branches of this circuit have an equivalent impedance equal to 3 ohms in series with the parallel combination of (5+20) ohms and (7.5+10) ohms. That value is ...
3 + (25)(17.5)/(25 +17.5) = 226/27 ≈ 13.294 . . . ohms
This, in turn, is in series with the 2.5 ohms in the bottom branch, bringing the total circuit resistance to about 15.794 ohms, or 537/34 ohms.
The total source current is then ...
I = V/R = (15 v)/(537/34 Ω) = 170/179 A ≈ 0.9497 A
_____
Alternate solutions
Alternatively, you can write and solve three node or loop equations for this circuit. For example, the equations for CCW loop currents, with I1 as the bottom loop, could be written in augmented matrix form as ...
[tex]\left[\begin{array}{ccc|c}27.5&-10&-15&-15\\-10&55&-25&0\\-15&-25&50&0\end{array}\right][/tex]
The result is the same.
*graph is below*
1. What is Peter’s total distance traveled? What is Peter's displacement?
2. Is there a time when Peter is not moving? If so, when?
The total distance covered is 24 Km and Peter was not moving between the points marked 10 mins and 30 mins on the graph. His displacement according to the graph is zero.
The distance time graph shows the distance covered plotted on the vertical axis against the time taken plotted on the horizontal axis. Using this graph, the total distance covered can easily be obtained.
The total distance covered is 12 km + 12 km since equal distance was covered to and fro. Hence the total distance covered is 24 km. Perter was not moving between the points marked 10 mins and 30 mins on the graph.
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Pls help me with this one :))
Answer:
Row A is correct
Explanation:
both conduction and convection require mass to complete any heat transfer. A vacuum contains no mass
During a picnic, you and two of your friends decide to have a three-way-tug-of-war, with three ropes in the middle tied into a knot. Roberta pulls to the west with 277 N of force; Michael pulls to the south with 603 N. a) With what force should you pull to keep the knot from moving
Answer:
Explanation:
I'm not 10% sure but i think that if you were to do:
603 + 277 = 880
1000 - 880 = 120
So to keep it from moving, i think you would need to pull with a force of 120N
The force with which it should be pulled to keep the knot from moving is 663.58 N.
What is Newton's third law ?Newton's third law states that, for every action, there is an equal and opposite reaction.
Here,
Force exerted by Roberta, F₁ = 277 N
Force exerted by Michael, F₂ = 603 N
Since, Roberta is pulling to the west and Michael is pulling towards the south, the angle between the forces applied by them is 90°.
The force needed to keep the knot from moving is the resultant force of these two forces.
Therefore, the resultant force,
Fₙ = √F₁² + F₂²
Fₙ = √(277)² + (603)²
Fₙ = 663.58 N
Hence,
The force with which it should be pulled to keep the knot from moving is 663.58 N.
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Heat is transferred from molecules with more kinetic energy to molecules with _________kinetic energy.
Answer:
less
Explanation:
heat travels from hotter to colder object. hotter object has more kinetic energy.
Which is the best way to avoid plagiarism? O use more than one source from your research O repeat information from your sources O present a topic in your own words O understand your topic before you begin writing
Answer:
O present a topic in your own words
Explanation:
Plagiarism is using someone else's words or work without giving them proper credit. Presenting a topic in your own words means you are not copying anyone.
Answer:
present a topic in your own words
Explanation:
URGENTLY NEED HELP!!!!!!
the stretch of a spring and the force it exerts are inversely proportional.
Select one:
O True
O False
Answer:
False.
Explanation:
An object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg. If this force serves as the action force, what is the reaction force in the action–reaction pair?
Answer:
Equal reaction from the pair in every action there's an equal and opposite reaction
The item will keep moving at a consistent speed if the object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg.
What is gravitational force?All mass-bearing objects are attracted by gravitational force. Because it consistently attempts to bring masses together rather than push them apart, the gravitational force is referred to as attractive.
As we know, the gravitational force is given by:
[tex]\rm F = \dfrac{Gm_1m_2}{r^2}[/tex]
Where G is the gravitational constant.
m1 and m2 are masses.
r is the distance between the masses.
It is given that:
An object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg.
As we know,
An object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg and the item will keep moving at a consistent speed.
Thus, the item will keep moving at a consistent speed if the object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg.
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A phone is dropped from the roof of the school building. The building is 13.2 meters high. How long was the phone in the air before it crashed on the ground?
Answer:
5scs
Explanation:
phones fall fast so i guessed
Name two environmental factors, one natural and one human-made, that could account for the trend or pattern in bird (quail, wren) and rodent (mice, rabbits) populations before 1997. Help!
Factors such as more crops, fewer predators, invasive species, and changes in the environment explain a decrease or increase in the birds and rodent populations.
Before 1997, both rodents and birds populations increased due to different factors. Moreover, these factors can be classified as natural or human-made factors. Here are the factors that mainly affected these animals:
Bird population:
Increase:
Decrease in predators that increase birds chances to survive (natural factor)
Increase in crops that improve food access for birds (human factor)
Decrease:
Invasive species or increase of predators (natural factor)
Destruction of natural habitats due to an increase in industry and extraction (human factor)
Rodent population:
Increase:
More adaptability that increased rodents chances to survive (natural factor)Increase in crops that improve food access for rodents (human factor)Decrease:
Invasive species or increase of predators (natural factor)Increase in rabbit consumption and use of rodent control products (human factor)Learn more in: https://brainly.com/question/18123593
5 What is the maximum speed at which a car round a curve of 25m radius on a level road if the coefficient of static friction between the tires and the road is 0.80?
Hi there!
On a level road:
∑F = Ff (Force due to friction)
The net force is the centripetal force, so:
mv²/r = Ff
Rewrite the force due to friction:
mv²/r = μmg
Cancel out the mass:
v²/r = μg
Solve for v:
v = √rμg
v = √(25)(9.81)(0.8) = 14.01 m/s
How much force must be applied to push a 1.35 kg book across the desk at constant speed if the coefficient of sliding friction is 0.30?
The magnitude of the force that must be applied to push the book across the desk is 3.97 N.
The given parameters;
mass, m = 1.35 kgcoefficient of friction, μ = 0.3The acceleration of the book across the desk is calculated as follows;
a = μg
where;
g is acceleration due to gravitya = 0.3 x 9.8
a = 2.94 m/s²
The magnitude of the force that must be applied is calculated as follows;
F = ma
F = 1.35 x 2.94
F = 3.97 N
Thus, the magnitude of the force that must be applied to push the book across the desk is 3.97 N.
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a mass of 7.5kg has a weight of 30n on a certain planet calculate the acceleration due to gravitt on this planet
Answer:
Acceleration due to gravity on a certain planet = 4 m/s²
Explanation:
According to the question,
Weight = 30 N
Mass = 7.5 kg
Let acceleration due to gravity be 'a'
Formula:
Weight = Mass × Acceleration due to gravity
30 = 7.5 × a
a = 30/7.5
a = 4 m/s²
The tires of a car make 77 revolutions as the car reduces its speed uniformly from 95.0 km/h to 65.0 km/h. The tires have a diameter of 0.90 m.
If the car continues to decelerate at this rate, how far does it go? Find the total distance.
Answer:
Explanation:
95.0 km/hr = 26.39 m/s
65 km/hr = 18.06 m/s
Circumference of a tire is 0.9π m
77 revolutions is a distance of
77(0.9π) = 69.3π m
v² = u² + 2as
a = (v² - u²) / 2s
a = (18.06² - 26.39²) / (2(69.3π))
a = -0.85 m/s²
s = (v² - u²) / 2a
s = (0² - 26.39²) / 2(-0.85)
s = 409 m
What are the two factors that affect the frictional force between objects
2. Jason rode his bike 10 miles and only rode for 2 hours how fast was he going?
Answer:
5 miles per hour.
Explanation:
10miles / 2hours = 5 mph
The current in the long wire is decreasing. What is the direction of the current induced in the conducting loop below the wire
Answer:
anlatamadım herkeze ben sorulara bakamiyorum cumku analmaiyirum yardim edin
bu sorunu nasil cozebilirim
lutfsn...
A car C moving with a speed of 65 km/h on a straight road is ahead of motorcycle M moving with the speed of 80 km/h in the same direction. What is the velocity of M relative to A?
Answer:
The answer is 15. Step by step is you times 80 by 65 and then you divided by 2 and you call your teacher
You have a 25 W and a 100 W bulb at home. When you connect one or the other, which bulb carries the greater current
Answer:
100 w bulb has more current.
Explanation:
P=V^2/R.
when velocity is constant power is inversly proportional to resistence, so 25 W will have an hogher resistance tjan a 100 w bulb.
P=VI
when v is constant, power is directly proportional to I. hence, 100 w bulbs will carry more current.
When you connect one or the other, the bulb that's connected carries more current than the one that's not connected.
When you connect BOTH of them, the 100W bulb carries more current than the 25W one.
A rod of length 0.82 m, rotating with an angular speed, 4.2 rad/s, about axes that pass perpendicularly through one end, has a mass of 0.63 kg, which is distributed uniformly along its length. Find the kinetic energies of the rod.
Answer:
Explanation:
KE = ½Iω²
ΚΕ = ½(mL²/3)ω²
ΚΕ = ½(0.63(0.82²)/3)4.2²
ΚΕ = 1.24541928
KE = 1.2 J
The force of earth’s gravity is 10N downward. What us the acceleration of a 15kg backpack if lifted with a a 15N force?
Answer:
F-F(gr) = ma
a= {F-F(gr)}/m =
=(15-10)/15=0.33 m/s² (upward)
How much heat must be removed from 1.61 kg of water at 0 ∘C to make ice cubes at 0 ∘C?
Answer:
Explanation:
All
Which processes result in the release of carbon? Select three options.
Animals break down food molecules to obtain energy.
The remains of producers are broken down by decomposers.
The remains of consumers are broken down by soil decomposers.
Producers take in carbon dioxide.
Producers make sugars and starches.
Answer:
The remains of producers are broken down by decomposers.
The remains of consumers are broken down by soil decomposers.
Animals break down food molecules to obtain energy.
Explanation:
Answer:
It is A. B. and C.
Explanation:
Hope this helps
PLZ HURRY
When you hold a racquet and swing your arm toward the ball, there are two kinds of resistance working against your muscles—the ______ and the ______.
A.
racket, air
B.
air, ball
C.
ball, net
D.
air, racket
Answer:
It should just be A
Explanation:
I dont see the difference between these 2 but ill choose A and update you
Answer:
A: racket, air
Explanation:
A grinding wheel is a uniform cylinder with a radius of 8.50 cm and a mass of 0.380 kg. Calculate (a) its moment of inertia about its center, and (b) the applied torque needed to accelerate it from rest to 1750 rpm in 5.00 s. Take into account a frictional torque that has been measured to slow down the wheel from 1500 rpm to rest in 55.0 s.
Hi there!
(A)
A grinding wheel is the same as a disk, having moment of inertia of:
[tex]I = \frac{1}{2}MR^2[/tex]
Plug in the given mass and radius (REMEMBER TO CONVERT) to find the moment of inertia:
[tex]I = \frac{1}{2}(0.380)(0.085)^2 = 0.00137 kgm^2[/tex]
(B)
We can use the rotational equivalent of Newton's Second Law to calculate the needed torque:
Στ = Iα = τ₁ - τ₂
Begin by solving for the angular acceleration. Convert rpm to rad/sec:
[tex]\frac{1750r}{min} * \frac{1 min}{60 s} * \frac{2\pi rad}{1 r} = 183.26 rad/sec[/tex]
Now, we can use the following equation:
ωf = wi + αt (wi = 0 rad/sec, from rest)
183.26/5 = α = 36.65 rad/sec²
τ = Iα = 0.0503 Nm
Since there is a counter-acting torque on the system, we must begin by finding that acceleration:
[tex]\frac{1500r}{min} * \frac{1 min}{60 s} * \frac{2\pi rad}{1 r} = 157.08 rad/sec[/tex]
ωf = wi + αt
-157.08/55 = α = -2.856 rad/sec²
τ₂ = Iα = 0.0039 Nm
Now, calculate the appropriate torque using the above equation:
[tex]\Sigma\tau = \tau_1 - \tau_2[/tex]
[tex]\Sigma\tau + \tau_2 = \tau_1[/tex]
[tex]0.0503 + 0.0039 = \large\boxed{0.054 Nm}[/tex]
Two objects are being lifted by a machine. One object has a mass of 2 kg, and is lifted at a speed of 2
m/s. The other has a mass of 4 kg and is lifted at a rate of 3 m/s.
a. Which object has more kinetic energy while it is being lifted?
Answer:
Kinetic energy = (1/2) (mass) (speed²)
First object: (1/2) (2 kg) (2 m/s)² = 4 joules .
Second object: (1/2) (4 kg) (3 m/s)² = 18 joules .
The second object had more kinetic energy than the first one had.
Explanation:
Answer:
Kinetic energy = (1/2) (mass) (speed²)
First object: (1/2) (2 kg) (2 m/s)² = 4 joules .
Second object: (1/2) (4 kg) (3 m/s)² = 18 joules .
The second object had more kinetic energy than the first one had.
3. What can you infer about the position of the galaxies 100 million years before this telescope photo was taken
The galaxies are in constant motion so it can be inferred that their position will not be the same as a hundred million years ago.
A galaxy is a term to refer to the set of stars, gas clouds, planets, cosmic dust, dark matter, and energy gravitationally united in a more or less defined structure in the universe.
Galaxies are in constant motion because the elements that make them up are not static at any time; The galaxies rotate around the center of the galaxy. If they were still, the gravitational attraction would cause them to immediately fall towards the center of the galaxy: it is the same that would happen to the Earth and the other planets if they stopped rotating around the Sun, they would fall towards the Sun.
According to the above, it can be inferred that the galaxies after a while have moved from the place where they were last seen.
Note: This question is incomplete because there is some missing information. However, I can answer based on my general prior knowledge.
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