Having been kicked, a soccer ball rolls past a kid with a stopwatch. At the moment the ball passes the kid, it has an initial velocity of 4.0 m/s and the watch reads 10.0 s. If the watch reads 23.3 s when the ball stops rolling, what is its average acceleration?
The ball rolls to a rest from 4.0 m/s in a span of 23.3 s - 10.0 s = 13.3 s, so the average acceleration is
(0 - 4.0 m/s) / (13.3 s) ≈ -0.30 m/s²
11. How fast will a pebble be traveling 3 seconds after being dropped? (g = 9.8 m/s2)
A.-9.8 m/s
B.29.4 m/s
C.9.8 m/s2
D.29.4 m/s
A toaster is rated at 600W, when connected to a120-V source. What current does the toaster carry, and what is its resistance?
Explanation:
Given parameters:
Power of the toaster = 600W
Voltage = 120V
Unknown:
Current = ?
Resistance = ?
Solution:
The power in the circuit is related to resistance and current using the expression below;
P = IV
P = [tex]\frac{V^{2} }{R}[/tex]
P is the power
I is the current
V is the voltage
R is the resistance
To find the current;
I = [tex]\frac{P}{V}[/tex] = [tex]\frac{600}{120}[/tex] = 5A
Now, resistance;
V² = PR
R = [tex]\frac{V^{2} }{P}[/tex] = [tex]\frac{120^{2} }{600}[/tex] = 24ohms
Current, I=5A
Resistance, R=24 ohms
Firstly, let's write the given values:
Power, P=600W
Voltage, V=120V
To find:
Current, I=?
Resistance, R=?
Lets understand ohm's Law:
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.
Formula for Ohm's law:
[tex]V=I.R[/tex]
The relation between power, current and resistance can be represented as:[tex]P=I.V[/tex]
Or
[tex]P=\frac{V^2}{R}[/tex]
To find current:
[tex]I=\frac{P}{V}[/tex]
So on substituting given values,
[tex]I=\frac{600}{120} =5A[/tex]
To find resistance:
[tex]R=\frac{V^2}{P}[/tex]
So on substituting given values,
[tex]R=\frac{14400}{600} =24 \text{ohms}[/tex]
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A projectile rolls off a cliff with a velocity of 40 m/s. The cliff is 60 meters high.
1. Calculate the time the projectile takes to hit the ground
2. Calculate the distance the projectile travelled on the X-axis horizontally before hitting the ground
3. Calculate the impact velocity of the projectile on the Y-axis
4. Calculate the Resultant velocity V r
5. Calculate the angle at which the projectile hits the ground
6. Calculate Sine Θ
7. Calculate Tan Θ
8. A final Resultant Velocity Statement
Answer:
1) t = 3.45 s, 2) x = 138 m, 3) v_{y} = -33.81 m /s, 4) v = 52.37 m / s ,
5) θ = -40.2º
Explanation:
This is a projectile exercise, as they indicate that the projectile rolls down the cliff, it goes with a horizontal speed when leaving the cliff, therefore the speed is v₀ₓ = 40 m / s.
1) Let's calculate the time that Taardaen reaches the bottom, we place the reference system at the bottom of the cliff
y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
When leaving the cliff the speed is horizontal v_{oy}= 0 and at the bottom of the cliff y = 0
0 = y₀ - ½ g t2
t = √ 2y₀ / g
t = √ (2 60 / 9.8)
t = 3.45 s
2) The horizontal distance traveled
x = v₀ₓ t
x = 40 3.45
x = 138 m
3) The vertical velocity at the point of impact
v_{y} = I go - g t
v_{y} = 0 - 9.8 3.45
v_{y} = -33.81 m /s
the negative sign indicates that the speed is down
4) the resulting velocity at this point
v = √ (vₓ² + v_{y}²)
v = √ (40² + 33.8²)
v = 52.37 m / s
5) angle of impact
tan θ = v_{y} / vx
θ = tan⁻¹ v_{y} / vx
θ = tan⁻¹ (-33.81 / 40)
θ = -40.2º
6) sin (-40.2) = -0.6455
7) tan (-40.2) = -0.845
8) when the projectile falls down the cliff, the horizontal speed remains constant and the vertical speed increases, therefore the resulting speed has a direction given by the angle that is measured clockwise from the x axis
1000 kg car takes travels on a circular track having radius 100 m with speed 10 m/s. What is the minimum coefficient of static friction between tires and track needed to keep the car on circular path. *
A- 0.01
B- 0.05
C- 0.1
D- 0.2
Answer:
C. 0.1
Explanation:
Sean and Tommy are debating the positive and negative impacts of technology on environmental quality. Tommy is listing the negative impacts. Which of the following would help his argument? (2 points)
Grupp av svarsalternativ
Solar panels have become more effective due to technological improvements.
Technology has helped make recycling to be more efficient.
It has created new ways to clean up oil spills.
Factories contribute to air and water pollution.
Answer:
Factories contribute to air and water pollution.
Explanation:
PLZ HELP help me help help
Answer:
matter
Explanation:
Hope I helped :)
b. Interpret Data Solution A has a pH of 1.6.
Solution B has a pH of 4. Which solution
has a greater concentration of hydrogen
ions? Explain.
Answer:
Solution A has a pH of 6 and solution B has a pH of 8. Which of the following is true regarding the concentration of hydrogen ions in each solution? A) A has 100 times greater H+ concentration than B. B) B has 100 times greater H+ concentration than A. C) A has 7/9 of the H+ concentration of B. D) A has 9/7 of the H+ concentration of B. E) none of these
Explanation:
Hey im super sorry if i get this wrong :)
True or False. A compound is formed when two or more elements are combined to make a
new substance with its own properties.
Anyone?
Answer:
I believe It's true. Since from memory I KNOW a compound is formed when elements are combined chemically.
Answer: correct
Explanation: a compound is 2 or more elements formed to make a completely new thing. For example, water is a compound. Why? Well, water is h20. What is h20? It’s Hydrogen and Oxygen. Oxygen is also a compound. Another example is CO2 (carbon dioxide) it’s made of carbon and oxygen, so it’s a compound! A element is just a pure substance. It’s not made up of other materials. It’s in its purest form.
how can voltage be produced by magnetism and motion?
Answer:
Electromagnetic Induction by a Moving Magnet
Then the action of moving a coil or loop of wire through a magnetic field induces a voltage in the coil with the magnitude of this induced voltage being proportional to the speed or velocity of the movement.
Explanation:
When water changes from a gas in the atmosphere to a liquid droplet in a cloud, this is known as
Group of answer choices
transpiration
condensation
evaporation
precipitation
Answer:
Condensation
Explanation:
Answer:When water changes from a gas in the atmosphere to a liquid droplet in a cloud, this is known as
Group of answer choices
transpiration
condensation
evaporation
precipitation,←, that one is right
Explanation: so ur answer is precipitation
The first group of planets that are made of rock and closest to the sun
Answer:
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun
a 2000 kg car moving down the road runs into a 5000 kg stationary suv. The car applies a force of 1400 n on the suv what is the magnitude of force applied by the suv on the car
Answer:
F_suv= 49050 N
Explanation:
We are told that a 2000 kg car moving down the road runs into a 5000 kg stationary suv. The car applies a force of 1400 N on the suv.
Now, according Newton's first law of motion, an object will continue in it's present state of rest except it is acted upon by an external body.
This means the force acting on the stationary Suv is force of gravity.
Thus; F_suv = 5000 × 9.81
F_suv= 49050 N
if an object is moving with a velocity of 25m/s, an acceleration of 5m/s and has a travel time of 5s, what is the final velocity of the object?
V = at + V0
where v0 is the initial speed, a is the acceleration and t is the time.
So:
v = 5m/s^2*5s + 25m/s = 50 m/s
A baseball is thrown horizontally with a velocity of 44 m/s. It travels a horizontal distance of 18
m to the plate before it is caught. How long does the ball stay in the air?
A.0.41 sec
B.41 sec
C.4.1 sec
D.4 sec
Answer:
a 0.41
plug number into equation
A horizontal baseball pitch is launched at 44 m/s. The ball will stay for 4.1 sec (approx) in the air. Hence, option C is correct.
What is Velocity?The rate at which an object's position changes when observed from a specific point of view and when measured against a specific unit of time is known as its velocity.
Its SI unit is represented as m/s, and it is a vector quantity, it means that it has both magnitude and direction.
According to the question, the given values are :
Initial Velocity, u = 44 m/s,
Distance travelled, s = 18 m and,
Final velocity, v = 0.
Use equation of motion :
v = u + at
0 = 44 + (-9.8)t
t = 44 / 9.8
t = 4.3 (approx)
Hence, the time for which the ball stay in the air is 4.1 sec (approx).
To get more information about velocity :
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How long would it take a 500. W electric motor to do 15010 J of work?
.Why does it take double the applied force to move a mass double the size?
Explain this in terms of inertia,
Answer:
NVIDIA GeForce RTX 3080 10GB GDDR6X PCI Express 4.0 Graphics Card
Explanation:
A hockey puck is sliding on frictionless ice, in an Eastward direction. It collides with a second hockey puck, initially stationary, which then goes off in the Northern direction. What direction is the first hockey puck moving after the collision
Answer:
Southeast
Explanation:
We have to put into cognisance that the first hockey puck is moving in the eastern direction in the first instance, before it hits the other stationary hockey puck. And as such, on hitting the second puck, it's displacement is expected to differ, as a result of the collision. While the stationary puck will the move in the Eastern direction, it changes the direction of the first puck, from eastern to southeastern
A coiled telephone cord forms a spiral with 65.0 turns, a diameter of 1.30 cm, and an unstretched length of 65.5 cm. Determine the inductance of one conductor in the unstretched cord.
Answer:
[tex]L=1.07\ \mu H[/tex]
Explanation:
Given that,
No of turns in a coiled telephone cord is 65
The diameter of the coil, d = 1.3 cm = 0.013 m
Radius, r = 0.0065 m
Unstretched length of the coil, l = 65.5 cm = 0.655 m
We need to find the inductance of one conductor in the unstretched cord. The formula for the inductance is given by :
[tex]L=\dfrac{\mu_oN^2 A}{l}\\\\L=\dfrac{4\pi \times 10^{-7}\times (65)^2\times \pi (0.0065)^2}{0.655 }\\\\L=1.07\times 10^{-6}\ H\\\\L=1.07\ \mu H[/tex]
So, the inductance of one conductor in the unstretched cord is [tex]1.07\ \mu H[/tex].
How does temperature effect density and the flow of convection currents?
Answer:
Convection
Explanation:
Convection is heat transfer due to a density differential within a fluid. As water's temperature increases in the presence of a heat source, it will become less dense and rise. As it moves up and away from the heat source, it cools and becomes more dense and sinks.
Regular exercise can:
A.
Reduce stress and anxiety
B.
Boost your immune system
C.
Increase your overall feeling of wellness
D.
All of the above
Answer:
D
Explanation:
After school, a student rides his bike back home. The student lives 750 meters from the school. If it takes the student 3 minutes to get home, what is his average speed?
Answer:
(4,5) and (8,10) what is the slope
Explanation:
After school, a student rides his bike back home. The student lives 750 meters from the school. If it takes the student 3 minutes to get home, what is his average speed?
Two hockey players are about to collide on the ice. One player has a mass of
66 kg and is traveling at 1.5 m/s north. The other has a mass of 75 kg and is
traveling at 1.2 m/s south. The system consists of the two tlockey players.
According to the law of conservation of momentum, what is the total
momentum of the system after they collide? Assume the collision is an
elastic collision.
A. 189 kg-m/s south
O B. 9 kg-m/s north
C. 189 kg.m/s north
D. 9 kg m/s south
Answer:
Option B: 9 kg.m/s North
Explanation:
We are told;
One player has a mass of
66 kg and is traveling at 1.5 m/s north.
Thus, velocity is positive since it's acting in the positive direction upwards.
Thus;
m1 = 66 kg
v1 = 1.5 m/s
Also, The other has a mass of 75 kg and is traveling at 1.2 m/s south.
Since it's traveling south, it means that velocity is negative. Thus;
m2 = 75 kg
v2 = -1.2 m/s
From conservation of mass, total momentum is;
m_total = m1•v1 + m2•v2
m_total = (66 × 1.5) + (75 × -1.2)
m_total = 99 - 90
m_total = 9 kg.m/s
This is positive and thus it will be in the direction of the north.
Answer:
9 kg-m/s north
Explanation:
Ken Griffey, Jr's warehouse shot in the 1933 home run derby travelled 93 feet per second for 5 seconds. How far did he hit the ball?
Answer:
465 feet because 93*5 = 465, btw that was 1993 not 1933
Explanation:
The picture below shows a science model made with a balloon, cord, and radiosonde.
Image showing a science model made with a balloon; at the bottom of the balloon is a cord with a radiosonde attached to it.
Which of these is most likely the function of the science model?
To change the density of air
To increase the humidity in air
To reduce the atmospheric pressure
To predict extreme weather conditions
Answer:
Since the person above didn't answer correctly I will, the correct option is (D) this is because the picture shown is of a weather balloon and the purpose of this device is to predict weather and its conditions
Hope this helped! (: Have a nice day
Answer: To predict extreme weather conditions
A radiosonde is a small tool that is put under a balloon filled with either hydrogen or helium. As the radiosonde goes up it measures pressure, temperature, and relative humidity.
A carbon ion with 10 electrons and 6 protons would have a charge of ?
Answer:
-4
Explanation:
Electrons are negative while protons are positive.
To find the charge, add the number of protons to the number of electrons.
6+(-10)
6-10
-4 is the charge
If a star appears to wobble back back and forth, or its light seems to change in brightness, what might be the cause?
Answer:
The first method, known as the wobble method, looks for changes in a star's relative velocity caused by the gravitational tug of a nearby planet. ... If a planet's orbit crosses between its parent star and Earth, it will block some of the light and cause the star to dim.
Explanation:
We all know that the chains of gravity shackle a planet to its star. That star's enormous gravitational influence keeps its planetary family in orbit. But gravity works both ways: as the planets sweep around in their orbits, they tug on their parent stars to and fro, causing those stars to wobble
Answer:
The way it’s orbiting
Explanation:
Which change of state is shown in the model?
-condensation
-deposition
-boiling
-freezing
Answer: what’s the model
Explanation:
it's B hope this help's
How do covalentes bonds form
A 60-kg woman runs up a staircase 15 m high (vertically) in 20 s.
Required:
a. How much power does she expend?
b. What is her horsepowerrating.
Answer:
(a) 441 W (b) 0.59 hP
Explanation:
Given that,
Mass of a woman, m = 60 kg
Height of a staircase, h = 15 m
Time, t = 20 s
(a) We need to find the power she expend. Work done per unit time is called power. It is given by :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{mgh}{t}\\\\P=\dfrac{60\times 9.8\times 15}{20}\\\\P=441\ W[/tex]
( b) Since, 1 hP = 745.7 W
P = 0.59 hP