Answer:
a) Please see below as the answer is self-explanatory.
b) 1. vertically downward
2. vertically upward
3 N/A
4 vertically downward.
Explanation:
a)
If the book is hold by the hand, this means (according to Newton's third law) that both exert a force on each other, equal and opposite.In this case this pair is formed by normal forces, the normal force (upward) that the hand does on the book (avoiding it to be accelerated downward) and the normal force that the book does on the hand (downward) avoiding it to be accelerated in the upward direction.The other force that acts on the book is the one due to gravity, and is always downward, which is numerically equal to the normal force that the hand does on the book, due to the book is at rest. There is no interaction between the book and the floor, so there is no force between them, neglecting the gravitational attraction between their masses.A baseball is thrown a distance of 20 m what is its speed if it takes 0.5 seconds to cover the distance
Answer:
40m/s
Explanation:
A diagram of a plant cell is shown below.
Which organelle is found in both plant and animal cells?
Cell membrane
Chloroplast
Ο Ο Ο
Large Vacuole
Cell Wall
Answer:
The Cell Membrane is found in both plant and animal cells.
Explanation:
Chloroplast, Large Vacuole and Cell Wall are all found in plant cells.
Arrange the following substances from the lightest to the heaviest:
Cl2, CH4; H20; NH3, N2
A. H2O<NH,< N2 CH4Cl2
B. CH< NH< H-0< < Cl2
C. Ny< Cl< H2O< CH«<NH3
D. NH;< CH«< Cl< H2O< N2
molecular weights are written in the picture.
CH4<NH3<H2O<Cl2
A train car, which has a mass of 2000 kg, is rolling along with a velocity of 20 m/s East. It
strikes a stationary car, which also has a mass of 2000 kg, and they stick together after the
collision. What is their final velocity? (include appropriate units in your answer) * 15
10m/s East
Explanation:
p=mv
m1v1 = m2v
p = m1v1
2000kg*(20m/s) = 40000kg*m/s
Add the two masses together for m2
p = m2v2
40000kg*m/s = 4000kg * v2
v2 = 10m/s
Sections or chunks of material where atoms are lined up with each other are called...
Answer:
Magnetic domains
Explanation:
Because when the electrons spin around the necleus of an atom, it causes the atom to become a tiny magnet
Energy is radiated or transmitted in the form of rays or waves or particles.
B. radiation
C. convection
D. conduction
Answer:
B radiation
Explanation:
every type of transmitted waves are radioactive in a way.
In fatal crashes, more than __________% of passenger car occupants who were totally ejected from the vehicle were killed.
Answer:
it would be 83% in a fatal crash.
how could you increase the gravitational potential energy of an object without changing its mass and gravity
given that two vectors A=i,2j-2k and B=6i+3j+2k find A +B
Answer:
7i, 5j, 0k
Explanation:
Add up the two vectors.
Add
i+i 1+6 = 7i
j+j 2+3 = 5j
k+k -2+2 = 0k
therefore A+B = (7i, 5j, 0k)
A 1.6 kg ball is attached to the end of a 0.40 m string to form a pendulum. This pendulum is released from rest with the string horizontal. At the lowest point of its swing, when it is moving horizontally, the ball collides with a 0.80 kg block that is at rest on a horizontal frictionless surface. The speed of the block just after the collision is 3 m/s. What is the speed of the ball just after the collision
Answer:
the speed of the ball just after the collision is 1.5 m/s.
Explanation:
Given;
mass of the ball, m₁ = 1.6 kg
initial velocity of the ball, u₁ = 0
mass of the block, m₂ = 0.8 kg
initial velocity of the block, u₂ = 0
final velocity of the block, v₂ = 3 m/s
let the final velocity of the ball after collision = v₁
Apply the principle of conservation of linear momentum for elastic collision;
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
1.6 x 0 + 0.8 x 0 = 1.6 x v₁ + 0.8 x 3
0 = 1.6v₁ + 2.4
-1.6v₁ = 2.4
v₁ = -2.4 / 1.6
v₁ = - 1.5 m/s
v₁ = 1.5 m/s (in opposite direction of the block)
Therefore, the speed of the ball just after the collision is 1.5 m/s.
A 55.0 kg bungee jumper steps off a bridge with a light bungee cord tied to her and to the bridge. The unstretched length of the cord is 15.0 m. She reaches the bottom of her motion 40.0 m below the bridge before bouncing back. Her motion can be separated into an 15.0 m free-fall and a 25.0 m section of simple harmonic oscillation. Use the principle of conservation of energy to find the spring constant of the bungee cord.
Answer:
[tex]69.06\ \text{N/m}[/tex]
Explanation:
m = Mass of bungee jumper = 55 kg
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
h = Height at the bottom = 40 m
k = Spring constant
x = Displacement of bungee cord = 25 m
Applying the principle of conservation of energy to the system we have
[tex]mgh=\dfrac{1}{2}kx^2\\\Rightarrow k=\dfrac{2mgh}{x^2}\\\Rightarrow k=\dfrac{2\times 55\times 9.81\times 40}{25^2}\\\Rightarrow k=69.06\ \text{N/m}[/tex]
The spring constant of the bungee cord is [tex]69.06\ \text{N/m}[/tex].
When will heat STOP flowing
between two objects?
A. When one object is significantly
warmer than the other
B. When one object is significantly cooler
than the other
C. Never
D. When both objects reach the same
temperature
Answer: D. When both objects reach the same temperature.
Explanation: When will heat flow between the objects stop? Heat will always flow from the warmer object to the colder object. The heat transfer will stop when the two objects are at the same temperature and reach thermal equilibrium.
Answer: Heat will always flow from the warmer object to the colder object. The heat transfer will stop when the two objects are at the same temperature and reach thermal equilibrium.
so the answer to your question is c
Explanation:
Which types of reactions are also redox reactions?
Answer:
Your ans is B)
Explanation:
Hope its right
if wrong firgive me
PLEASE HELP
The spine is part of which system?
A. Circulatory System
B. Central Nervous System
C. Endocrine System
Answer:
Explanation:
B. Central Nervous System
A Cambra pouce car traveling at 28 m/s slow
at a rate of at 3.6 m/s every second find.
a) The time taken for the police car to come to Stop?
Answer:
t = 7.8 seconds
Explanation:
Given that,
The initial speed of the car, u = 28 m/s
Acceleration of the car, a = 3.6 m/s²
We need to find the time taken for the police car to come to Stop. When it stops, its final speed is equal to 0. So, using the equation of kinematics to find it i.e.
[tex]v=u+at\\\\0=28+3.6t\\\\t=\dfrac{28}{3.6}\\\\t=7.8\ s[/tex]
So, the required time is 7.8 seconds.
how much force is needed to accelerate a 2500kg car at a rate of 4m/s2
Answer:
10,000 N
Explanation:
Using Newton's Second Law of Motion, Force = Mass*Acceleration.
Plugin 2500 kg for the mass and 4 m/s^2 for the acceleration.
Force = 2500 kg*4 m/s^2 = 10000 Newtons
(SI unit of force is Newtons)
Need a little help here, ASAP please. The subject is simple science, not physics.
What would be the orbital speed and period of a satellite in orbit 1.44 × 10^2 m above Earth?
mass of earth = 5.97x 10 ^ 24 kg , radius of earth = 6.38 x10^6m
pls help
Explanation:
Given that,
We need to find the orbital speed and period of a satellite in orbit [tex]1.44\times 10^2\ m[/tex] above Earth.
The formula for the orbital speed is given by :
[tex]v=\sqrt{\dfrac{GM}{r}} \\\\v=\sqrt{\dfrac{6.67\times 10^{-11}\times5.97\times 10^{24}}{(1.44\times 10^2+6.38\times 10^6)^2}} \\\\v=3.12\ m/s[/tex]
Let T be the time period of the satellite. It can b solved using Kepler's third law i.e.
[tex]T^2=\dfrac{4\pi^2}{GM}r^3\\\\T^2=\dfrac{4\pi^2\times (1.44\times 10^2)^3}{6.67\times 10^{-11}\times 5.97\times 10^{24}}\\\\T=5.44\times 10^{-4}\ s[/tex]
Hence, this is the required solution.
The orbital speed of the satellite is 3.13 m/s and the period of the satellite in orbit is 5.44 × 10⁻⁴ s.
The orbital speed of an astronomical object in a gravitational system is the speed at which it revolves around the central point or the speed required to keep an artificial or natural satellite in orbit.
It can be expressed by using the formula:
[tex]\mathbf{v = \sqrt{\dfrac{GM}{r}}}[/tex]
where;
v = orbital velocity of the satelliteG = gravitational constant = 6.67 × 10⁻¹¹M = mass of the satellite body (earth) = 5.97 x 10²⁴ kgr = radius of the satellite
[tex]\mathbf{v = \sqrt{\dfrac{6.67 \times 10^{-11} \times 5.97 \times 10^{24}}{(1.44 \times 10^2 + 6.38 \times 10^6)^2}}}[/tex]
v = 3.13 m/s
In planetary motion, Kepler's third law states that the square of the period of a planet varies directly proportional to the cubes of the planets' mean distances (d).
The period of the satellite can be estimated by using Kepler's third law. It can be computed by using the formula:
[tex]\mathbf{T^2 =\dfrac{4 \pi^2}{GM}\times r^3}[/tex]
[tex]\mathbf{T^2 =\dfrac{4 \pi^2}{6.67 \times 10^{-11} \times 5.97 \times 10^{24}}\times (1.44 \times 10^2)^3}[/tex]
[tex]\mathbf{T^2 =2.96037718\times 10^{-7}}[/tex]
[tex]\mathbf{T =5.44 \times 10^{-4} \ s}[/tex]
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I need help with science please, ill give brianlist’s :
Question 1 :The size of a plant cell may change depending upon the amount of water it receives.
True
False
________________________________
Question 2: Chloroplasts are a category of organelles found in the cells of green plants.
True
False
_______________________________
Question 3: Photosynthesis in plants produces water and carbon dioxide.
True
False
Answer:
true , true, and I'm not sure about the last one!
Explanation:
PLEASE HELP ME WITH THIS ONE QUESTION
Two substances of different temperatures are brought into thermal contact. While the objects come to equilibrium, some heat is lost to the environment. How would that affect the final temperature?
A) it would be higher
B) it would change unpredictably
C) it would remain the same
D) it would be lower
Answer:
the correct is D
Explanation:
In the calorimetry exercises, if there are no losses, we assume that all the heat lost by one body is absorbed by the other, but if there are losses
Q_ {yielded} = Q_ {absent} + Q_ {lost}
Since energy cannot be created or destroyed, they only ask to change, therefore the term of the absorbed heat must decrease, consequently the final temperature of the system is lower when there is loss of energy.
When checking the answers, the correct one is D
. Four railroad cars, each of mass 2.50 104 kg, are coupled together and coasting along horizontal tracks at a speed of vi toward the south. A very strong but foolish movie actor, riding on the second car, uncouples the front car and gives it a big push, increasing its speed to 4.00 m/s southward. The remaining three cars continue moving toward the south, now at 2.00 m/s. (a) Find the initial speed of the cars. (b) How much work did the actor do
Answer:
a) v₀ = 2.5 m / s, heading south.
b) W = 1,219 10⁵ J
Explanation:
a) For this exercise we can use the conservation of the moment, we create a system formed by all the 4 cars, in this case when the last one separates the forces are intense and the moment is conserved
initial instant. Before separation
p₀ = M v₀
final instant. When uncoupling the last car
p_f = 3m v₁ + m v₂
where they indicate that the speed of the wagons is v₁ = 2.00 m / s and the speed of the last wagon is v₂ = 4.00 m / s
the total mass is M = 4m
how the moment is preserved
p₀ = p_f
4m v₀ = 3m v₁ + mv₂
v₀ = ¾ v₁ + v₂ / 4
let's calculate
v₀ = ¾ 2 + ¼ 4
v₀ = 2.5 m / s
heading south.
b) work is equal to the change in kinetic energy
W = ΔK = K_f -K_o
W = ½ m v_f² - ½ m v₀²
W = ½ m (v_f² -v₀²)
W = ½ 2.50 10⁴ (4² - 2.5²2)
W = 1,219 10⁵ J
Find the velocity of a dolphin that swims 55 m in 5.0 s.
Answer: 11 m/s
Explanation: velocity = distance /time = 55 m /5.0 s
Answer:40km/h
Explanation:
A 1.5 V battery produces 41.8 mA when it is across a 30.0 Ω load. The potential difference across the battery's terminals is
Answer:
Explanation:
V = I R
V = 0.0418 * 30
V = 1.254
this battery seems dead :P
Answer:
Explanation:
Let's just assume that the battery has no internal resistance. If we get an absurd answer, we'll come back and look at that assumption.
E = I * R
I = 41.8/1000 amps = 0.0418
R = 30.0 ohms
E = 0.0418 * 30
E = 1.254 volts. This is an OK answer. The battery is a little old.
Which bond(s) shown are double bonds?
Answer:
I'm pretty sure its the 2nd one.
How much is Coulomb's constant ?
Answer:
8.9875517923(14)×109 kg⋅m3⋅s−2⋅C−2
Explanation:
Exact number is 8.9875517923(14)×109 kg⋅m3⋅s−2⋅C−2
a car whose tires have radii of 50cm travels at 20km/h. what is the angular velocity of the tire
Answer:
0.225 s^-1
Explanation:
Please mark as brainliest
The angular velocity of the tire is 11.12 rad/s.
Angular velocity: This is the change in angular direction per time. The S.I unit is rad/s.
⇒ Formula:
v = rω.................... Equation 1⇒ Where:
v = linear velocity of the carr = radius of the carω = angular velocity of the car⇒ Make ω the subject of the equation
ω = v/r.............. Equation 2From the question,
⇒ Given:
v = 20 km/h = 20(1000)/(3600) m/s = 5.56 m/sr = 50 cm = 50/100 = 0.5 m⇒ Substitute these values into equation 2
ω = 5.56/0.5ω = 11.12 rad/sHence, The angular velocity of the tire is 11.12 rad/s
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faraday's law states that the potential difference can be increased by... (choose all that apply)
1. using static electricity instead of current electricity
2. increase the number of coils, increase the strength of the magnet
3. using a bunch of small magnets
4. increasing the time used to power up an electromagnet
5. increase the speed of the magnet
Id say its the last option of the fourth option
Explanation:
Answer:
1:increase the number of coils, increase the strength of the magnet
2:increase the speed of the magnet
3: increasing the time used to power up an electromagnet
Explanation:
1). Increasing the number of turns of wire in the coil – By increasing the amount of individual conductors cutting through the magnetic field, the amount of induced emf produced will be the sum of all the individual loops of the coil, so if there are 20 turns in the coil there will be 20 times more induced emf than in one piece of wire.
2). Increasing the speed of the relative motion between the coil and the magnet – If the same coil of wire passed through the same magnetic field but its speed or velocity is increased, the wire will cut the lines of flux at a faster rate so more induced emf would be produced.
3). Increasing the strength of the magnetic field – If the same coil of wire is moved at the same speed through a stronger magnetic field, there will be more emf produced because there are more lines of force to cut.
Please help
The period of an oscillation is measured to be 0.0833 seconds. What is
the frequency of this oscillation? *
1.0833 Hz
0.287 Hz
9.8 Hz
12 Hz
0.007 Hz
Answer:
your
answer is
12.004
g A 4 lb weight stretches a spring 2 ft in equilibrium. It is attached to a damping mechanism with constant c. (a) Find the value of c for which the motion is critically damped. (b) If the motion is critically damped, find the displacement y(t) when the spring is initially displaced 6 inches above equilibrium and given a downward velocity of 3 ft/sec.
Solution :
Given :
Weight = 4 lb
Stretched of a spring in equilibrium,Δ = 2 ft
a). We know that
F = kΔ
4 = k x 2
k = 2 lb/ft
∴ Stiffness of the spring is, k = 2 lb/ft
Motion is critically damped.
[tex]$\epsilon = 1$[/tex]
[tex]$\epsilon=\frac{C}{C_c} = 1$[/tex]
[tex]$C=C_c[/tex]
[tex]$C=C_c=\sqrt{4k_m}[/tex]
[tex]$C=\sqrt{4 \times 2 \times \left(\frac{4}{32.174}\right)}[/tex]
C = 0.99729 lb.s/ft.
b). Displacement
[tex]$y(t)=y_0 \sin (\omega t)$[/tex]
[tex]$\dot{y}(t)= y_0 \omega \cos (\omega t)$[/tex]
[tex]$[\dot{y}(t)]_{mon}= y_0 \omega $[/tex]
Initial displacement = 6 inches
[tex]$y_0 = 0.5 \ ft , \ \ \ \dot y (t) = 3 \ ft/sec$[/tex]
[tex]$\Rightarrow 3=0.5 \times \omega$[/tex]
[tex]$\Rightarrow \omega = 6$[/tex]
Therefore, displacement :
[tex]$y(t)=y_0 \sin (\omega t)$[/tex]
[tex]$y(t)=0.5 \sin (6 t)$[/tex]
What happens when a tennis racket hits
a ball?
A. The ball pushes back on the racket in the opposite
direction.
B. The ball pushes back on the racket in the same
direction.
C. The ball does not push back on the racket.
D. The ball pushes back on the racket perpendicularly.
Newton's third law of motion states that for every action, there is an equal and opposite reaction. When a tennis racket hits a ball A. The ball pushes back on the racket in the opposite direction.
When a tennis racket hits a ball, the ball exerts a force on the racket, and according to Newton's third law of motion, the racket exerts an equal and opposite force on the ball. This means that the ball pushes back on the racket in the opposite direction to which the racket struck the ball.
This principle is often referred to as "action-reaction" or "equal and opposite forces." When the racket collides with the ball, the force applied by the racket causes the ball to accelerate in the opposite direction, leading to its movement away from the racket.
Therefore, when a tennis racket hits a ball A. The ball pushes back on the racket in the opposite direction.
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