Answer:
(a) 0.42 m/s²
(b) 83 N
Explanation:
Assuming g = 10 m/s².
Draw free body diagrams for the child and the chair.
There are three forces on the child:
Tension force T pulling up,
Weight force Mg pulling down,
and normal force N pushing up.
There are three forces on the chair:
Tension force T pulling up,
Weight force mg pulling down,
and normal force N pushing down.
Sum of forces on the child in the y direction:
∑F = ma
T + N − Mg = Ma
Sum of forces on the chair in the y direction:
∑F = ma
T − N − mg = ma
Add the equations together to find the acceleration.
2T − Mg − mg = Ma + ma
a = (2T − Mg − mg) / (M + m)
a = g (2T − Mg − mg) / (Mg + mg)
a = (10 m/s²) (2 × 250 N − 320 N − 160 N) / (320 N + 160 N)
a = 0.42 m/s²
Plug into either equation to find the normal force.
T + N − Mg = Ma
250 N + N − 320 N = (320 N / 10 m/s²) (0.42 m/s²)
N = 83 N
A student uses a spring scale attached to a textbook to compare the static and kinetic friction between the textbook and the top of a lab table. If the scale measures 1,580 g while the student is pulling the sliding book along the table, which reading on the scale could have been possible at the moment the student overcame the static friction?
Answer:1860g
Explanation:The force would have to be greater than 1580g, which is when the student is pulling the sliding book with the spring scale
If a car has a speed of 36m/s how long will it take to go 100 m
7. Calculate the force applied on an object if the Pressure exerted is 90 Pascal over an area of 900 cm2.
Answer:
Explanation: pressure = force / area
Rearrange to get: force = pressure x area. 900 cm2 = 0.09 m2
force = 90 x 0.09
= 8.1 N
Hi :) how to do this?
Answer:
The answer is b
Hope this helps you!
An aircraft travelling at 600km/h accelerates steadily at 10km/h per second. Taking the speed of sound as 1100km/h at the aircraft's altitude how long will it take to reach the sound barrier?
speed of sound is the final velocity [tex] v=1100[/tex]
and initial velocity $u=600$ , $a=10$
$v=u+at$
$t=\dfrac{v-u}{a}= \dfrac{500}{10}$
$\implies t=50 h$
the resistance per meter is 10 ohm. if the resistance of the material of the wire is 50 then 10^-8 ohm. find the area of cross section of the wire.
the question is at some point wrong or missing a word please help me with the question and answer!
Answer:
5×10⁻⁸ m²
Explanation:
I assume you mean the resistivity of the material is 50×10⁻⁸ Ωm.
R = ρL/A
10 Ω = (50×10⁻⁸ Ωm) (1 m) / A
A = 5×10⁻⁸ m²
Which describes a grizzly bear’s habitat? all the biotic factors in the ecosystem all the abiotic factors in the ecosystem the role of the bear in the ecosystem the physical area where the bear lives
Answer:
I found this question elsewhere on brainly and the answer was verified. Here it is!
Explanation:
Grizzly bear habitats is the habitat or the physical space where the bear lives. Grizzly bears can be found in many different habitats from dense forests to subalpine meadows, arctic tundra and open plains. We can also conclude that all of the bears live in grizzly bear's habitat in order to survive.
The best description of a grizzly bear’s habitat is:
D. the physical area where the bear livesA habitat is the natural surrounding or place where an organism lives, grows and competes with other organisms for resources. It is a physical area.
There are three major types of habitat which includes:
Freshwater habitat: This refers to the area of water where animals live. Examples of animals that live in a freshwater habitat includes: sea turtle, fishes, etc. Examples of freshwater habitat include:RiversLakesPond, etcMarine water habitat: This is where a group of organisms live. Examples include:OceansSeas, etc.Coastal habitat: This is an intersection between the land and sea habitats.A grizzly bear is a subspecies of brown bear and is resident in the northern plains of America and their habitat is a physical location where they live.
Therefore, the correct answer is option D
Read more here:
https://brainly.com/question/19482426
why do objects in equilibrium have a net force of 0?
Answer:
Because there is no net force acting o an object in equilibrium.
Explanation:
When object is in equilibrium (either at rest or moving with constant velocity, the net force acting o it is zero.A vector can only have zero magnitude fall of its components are zero this means that all forces acting on the object are balanced.
Which of these is an example of an elastic collision? A. The cue ball crashing into the eight balls on a pool table. B. Two cars colliding in an accident and moving together in the end. C. A kid landing a flip on a trampoline.
Answer:
The cue ball crashing into the eight balls on a pool table.
Explanation:
Elastic and inelastic collisions are two types of collisions.
For elastic collision, both the momentum and the kinetic energy before and after the collision remains conserved.
Out of the given options, the option that shows an example of an elastic collision is option A " The cue ball crashing into the eight balls on a pool table." All the eight balls after crashing moves with different velocity.
How do parts of a fancy cup (metal like cup) work together to keep a drink cold?
Answer:
“They may feel colder but that's only an illusion,” Dr. Begley says. “Copper mugs actually absorb heat from the room faster than a glass.” Copper is an excellent thermal conductor, meaning it transfers heat from hot sources (like the room or your hand) to cold sources (like your drink) very efficiently.
Explanation:
Match the words to the correct blanks in the sentences. Use each choice only once. a. The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by________. b. As a protostar shrinks in size, its central temperature rises along with its________. c. A star that has not yet finished forming is called a_______. d. A forming star spins more rapidly as it collapses because of conservation of________. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a________.A. thermal pressureB. angular momentumC. energy balanceD. degeneracy pressureE. brown dwarfF. gravitational equilibriumG. protostar
Answer:
The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____
Calculate the current passing through a conductor of resistance 4ohms. If a potential difference of 15V its ends______
Explanation:
current = velocity/resistance
I = V/R
15/4
current = 3.75A
hope this helps...
Describe the motion of water waves.
Answer:
Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases.
What is the Opportunity Cost in textbooks from going from point A to B?
Answer:
60.00
Explanation:
you welcome
please help ASAP.
these are examination questions ..
no nonsense answers .
i will mark as brainliest if you got it correct .
Answer:
1st question c part
2nd question c part
If a suitcase has a mass of 20 kg, what is the force of gravity acting on it?
Explanation:
Assuming the suitcase is near the surface of the earth, g = 9.8 m/s².
F = ma
F = (20 kg) (9.8 m/s²)
F = 196 N
A 310 turn solenoid with a length of 18.0 cm and a radius of 1.60 cm carries a current of 1.90 A. A second coil of four turns is wrapped tightly around this solenoid, so it can be considered to have the same radius as the solenoid. The current in the 310 turn solenoid increases steadily to 5.00 A in 0.900 s.(a) Use Ampere's law to calculate the initial magnetic field in the middle of the 310 turn solenoid.T(b) Calculate the magnetic field of the 310 turn solenoid after 0.900 s.T(c) Calculate the area of the 4-turn coil.m2(d) Calculate the change in the magnetic flux through the 4-turn coil during the same period.Wb(e) Calculate the average induced emf in the 4-turn coil.VIs it equal to the instantaneous induced emf? Explain.(f) Why could contributions to the magnetic field by the current in the 4-turn coil be neglected in this calculation?
Answer:
Given that;
Number of turns in the solenoid N = 310
Length of the solenoid L = 18 cm = 0.18 m
Radius of the solenoid r = 1.60 cm = 0.016 m
Current in the first Circuit I₁ = 1.90A
Number of turns in second coil N₂ = 4
Final Current solenoid I₂ = 5.0 A
Time interval to change the time Δt = 0.9 s
a)
According to Ampere's law, magnetic field inside a conductor is calculated as;
B₁ = ц₀N₁I₁ / L
(ц₀ = 4π × 10⁻⁷ constant)
therefore we substitute
{(4π × 10⁻⁷) × 310 × 1.9A} / 0.18m
= 0.0041 T
b)
Magnetic field inside the solenoid after t = 0.9
B₁ = ц₀N₁I₂ / L
= {(4π × 10⁻⁷) × 310 × 5.0A} / 0.18m
= 0.0108 T
c)
Area of coil is
A = πr²
A = π × ( 0.016 )²
A = 0.000804 m²
d)
Change in magnetic influx is
dФ = (B₂ - B₁) A
= ( 0.0108 T - 0.0041 T) × 0.000804 m²
= 0.0000053868 ≈ 5.39 × 10⁻⁶
e)
Average induced emf is
e = -N₂ ( dФ / dt )
e = ( -4 ) ( 5.39 × 10⁻⁶ / 0.9)
e = - 2.39 × 10⁻⁵V ( NOTE, this is not equal to the instantaneous induced emf )
f)
The induced emf is very low, so the contributions to the magnetic field in the coil is Negative.
A 1.00-kg glider attached to a spring with a force constant 25.0 N/m oscillates on a frictionless, horizontal air track. At t = 0, the glider is released from rest at x = -2.80 cm (that is, the spring is compressed by 2.80 cm). (a) Find the period of the glider's motion. How does the period depend on the mass and the spring constant? Does it depend on the amplitude of oscillation? s (b) Find the maximum values of its speed and acceleration. speed m/s acceleration m/s2 (c) Find the position, velocity, and acceleration as functions of time. (Where position is in m, velocity is in m/s, acceleration is in m/s2, and t is in s. Use the following as necessary: t.) x(t) = v(t) = a(t) =
Answer:
a) T = 1.26 s , b) v_max = 0.14 m / s , a_max = 0.7 m / s²
c) x = 0.028 cos (5 t) , v = - 0.14 sin 5t, a = - 0.7 cos 5t
Explanation:
This is a simple harmonic motion exercise that is described by the equation
x = A cos (wt +Ф)
with
w = √ (k / m)
let's apply this expression to our case
a) Angular velocity is related to frequency
w = 2π f
frequency and period are related
f = 1 / T
we substitute
2π / T = √ (k / m)
T = 2π √(m / k)
let's calculate
T = 2π √(1/25)
T = 1.26 s
In the expression for the period, the amplitude does not appear, therefore there is no dependence, as long as Hooke's law is fulfilled, which is correct for small amplitudes.
b) in the initial equation we have the position as a function of time, let's use the definition of speed and acceleration
v = dx / dt
v = - A w sin (wt + Ф)
the speed is maximum when the sine is -1
v_max = A w
w = √ (k / m)
w = √ 25/1
w = 5 rad / s
the amplitude of the movement is equal to the maximum compression of the spring
A = 2.8 cm = 0.028 m
we substitute
v_max = 0.028 5
v_max = 0.14 m / s
acceleration
a = dv / dt
a = - A w² cos (wt + Ф)
the acceleration is maximum when the cosine is -1
a_max = A w²
let's calculate
a_max = 0.028 5²
a_max = 0.7 m / s²
c) let's start by finding the phase constant
v = -A w cos (wt + Ф)
at t = 0 they indicate that the system has v = 0
0 = -A w sin (0 + Ф)
Ф = sin⁻¹ 0
Ф = 0
we write the equation
x = 0.028 cos (5 t)
v = - A w sin (wt + Ф)
v = - 0.028 5 sin (5t + 0)
v = - 0.14 sin 5t
acceleration
a = - A w² cos (wt + Ф)
a = - 0.028 5 2 cos (5 t + 0)
a = - 0.7 cos 5t
Eli and Andy want to find out which of the two is stronger. Eli pushes a table with a force of 120 newtons while Andy pushes the table from the opposite side with a force of 125 newtons. Ignoring the masses of Eli and Andy, what is the resultant acceleration of the table if its mass is 10.0 kilograms?
Answer:
a = 0.5 m/s²
Explanation:
the type of problem is called a Newtons second law of motion.
and the equation would be the sum of F = m * a where m = mass and a = acceleration
forces are 125N and the opposite direction is 120N
Eli pushes the table with a force of 120N towards Andy
and
Andy pushes the table with a force of 125N towards Eli
mass of table given as 10 kg.
using the equation
120N - 125N = 10kg * a
a = (120-125) / 10
a = -0.5 m/s² so the acceleration is in the direction of Andy's force towards Eli.
therefore a = 0.5 m/s²
Answer:
B.
0.50 meters/second2
Explanation:
famous comparative and superlative form
Answer:
comparative----more famous, superlative----- most famous
[tex]\huge{\fbox{\red{Answer:}}}[/tex]
Word Given :Famous
___________________✍
Comparative Form : more famous
Superlative Form : most famous
Hope you understand❣
what is the distance fallen for a freely falling ojvect 1 s after being dropped from a rest position
Answer:
111op
Explanation:
Answer:
11op
Explanation:good job and work hard
Using your own word, tell me what is the difference between an element and a compound? Make sure to give an example of each.
Answer:
Hey there!
Elements only contain one type of atom, and a compound contains atoms of different elements chemically combined together. For example, gold is an element, because it only is made of gold atoms, where water or H2O is a compound.
Let me know if this helps :)
Answer:
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. Elements contain only one type of atom.
Example:
Explanation:
An object weighs 980N on the earth’s surface (i) What is its mass? (ii) If the same object weighs 360N on another planet, find the force of gravity on that planet.
what is the scientific notation for 1,500,000
Answer:
[tex]1.5 * 10^6[/tex]
Explanation:
Given
Digit: 1,500,000
Required
Represent using scientific notation
We start by expressing the given digit as a product of 1.5 and a multiple of 10
[tex]Digit = 1.5 * 1,000,000[/tex]
1,000,000 can be represented as 10⁶
So; the digit becomes
[tex]Digit = 1.5 * 10^6[/tex]
Hence, the scientific notation of 1,500,000 is 1.5 * 10⁶
a metre rod on wedge is example of unstable equilibrium.why
Answer:
because it has no balance
What is the goal of the scientific method
Answer:
Regardless of how the steps are documented, the goal of scientific method is to gather data that will validate or invalidate a cause and effect relationship.
Hope this helped!!!
*If someone says v-u=0 ,what does it mean. *What is the relation among mometum,mass and velocity. *A moving bus a little distance forward even when breaks are applied on it which Newton's laws work here? *Under what conditions acceleration of a moving object will be zero?
Answer:
1) It means that the acceleration is 0
2) Momentum, p = Mass, m × Velocity, v
3) Newton's second law of motion
4) The conditions where there are no resultant forces acting on the object
Explanation:
1) The value v - u = 0 means that the acceleration is 0
The relation between v and u is v = u + a·t
v - u = a·t
When v - u = 0 we have;
a·t = 0
a = 0 or t = 0
Acceleration, a = 0
2) The relation between momentum, mass and velocity is
Momentum, p = Mass, m × Velocity, v
p = m × v
3) The bus moving a little distance forward even when the breaks are applied is due to the following relation;
Force = Rate of change of momentum produced
Which is Newton's second law of motion
Therefore, where the the force is low, the rate of change of the momentum and therefore, the velocity will be low, and the bus will still move further after applying the breaks
4) According to Newton's first law of motion, the conditions under which the acceleration of a moving object will be zero includes conditions where there are no resultant forces acting on the object.
John owns a used 2003 mustang Mach 1, he spots a news crew with a bunch of people what should he do? A) Rev his engine at the highest RPM B) Do a burnout C) Drive near the Crowd and drop a gear and hurl into the crowd D) ALL OF THE ABOVE
Each of the three choices is tasteless, exhibitionist, juvenile, and dangerous. John should do none of them.
Encountering a news crew, there's no reason for John to call attention to himself in a childish way, or interfere with their work in any way.
What he should do is:
==> Slow down
==> Pass the scene cautiously
==> Resume his normal, legal speed quietly, in case the crew happens to be recording audio at the moment.
Mysteriously, this course of action is nowhere to be found among the choices listed.
Answer:
all three options :)
Explanation:
cuz merica
answer answer answer it it it
Answer:
Parachutes
Explanation:
Your parachute allows you to descend more slowly because it lowers terminal velocity by increasing your air resistance. Most parachutes are designed to create a large amount of drag and allow you to land at a safe, low speed.
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Is it (P)otential or (K)inetic energy
Answer:
Think of it like this potential energy is exactly what it sounds like it has potential. while kinetic energy which is what the body possesses by virtue of being in motion.
Explanation:
