Answer:
A convex lens or converging lens focuses the light rays to a specific point whereas a concave lens or diverging lens diverges the light rays. When these lenses are combined, they produce sharper images. Most of the eyeglass lenses use combinations of convex and concave lenses.
Polar dissolves
A. nonpolar
B. polar
C. all molecules
D. none of the above
Polar substances are likely to dissolve in polar solvents.
Your answer is B.
5
A cyclist travels 125 km in 5 hours. How fast is the cyclist moving?
Answer:
25 km/h
Explanation:
speed=distance÷time
125÷5=speed
125÷5=25 (then add units)
A wheel of mass 50 kg has a radius of 0.4 m. It is making 480 rpm. What is the
torque necessary to bring it to rest in 40 seconds?
Solution:
Answer:
The torque necessary to bring the wheel to rest in 40 seconds is 10.4 N·m
Explanation:
The question is with regards to rotational motion
The rotary motion parameters are;
The mass of the wheel = 50 kg
The radius of the wheel = 0.4 m
The rate of rotation of the wheel = 480 rpm
The time in which the wheel is to be brought to rest = 40 s
The rotational rate of the wheel in rotation per second is given as follows;
480 r.p.m = 480 r.p.m × 1 minute/(60 seconds) = 8 revolution/second
1 revolution = 2·π radians
Therefore, we have the angular velocity, ω, given as follows;
ω = 2·π × 8 revolutions/second ≈ 50.3 rad/s
The angular acceleration, α, is given as follows;
[tex]\alpha = \dfrac{\Delta \omega}{\Delta t} = \dfrac{\omega _2 - \omega_1}{t_2 - t_1}[/tex]
Whereby the wheel is brought to rest from its initially constant rotational motion in 40 seconds, we have;
ω₁ ≈ 50.3 rad/s, ω₂ = 0 rad/s, and t₂ - t₁ = 40 seconds
Plugging in the values for the variables of the equation for the angular acceleration, "α", we get;
[tex]\alpha = \dfrac{0 - 50.3 \ rad/s}{40 \ s} \approx 1.3 \ rad/s^2[/tex]
The torque on the wheel, τ, is given as follows;
τ = m·r²·α
Where;
m = The mass of the object = 50 kg
r = The radius of the wheel = 0.4 m
α = The acceleration of the wheel ≈ 1.3 rad/s²
Therefore;
τ = 50 kg × (0.4 m)² × 1.3 rad/s² ≈ 10.4 N·m
The torque necessary to bring the wheel to rest in 40 seconds = τ ≈ 10.4 N·m.
Answer:
-10.048 N m
Explanation:
Which image illustrates the bouncing of a light wave off of a surface?
A
B
с
D
A. A
B. B
C. C
Answer:
The answer is A good luck :P
Answer:
A
Explanation:
The light Bounces off because it is reflecting off glass or anything else
Electromagnetic waves are classified as longitudinal waves.
Please select the best answer from the choices provided
T
F
Answer:
False
Explanation:
Electromagnetic waves are transverse waves. That means that the electric and magnetic fields oscillate in a plane that is perpendicular to the direction of wave propagation.
Answer:
false electromagnetic waves are not classified as longitudinal waves
Look at the atoms below
a. Atom W: 9 protons and 9 neutrons
b. Atom X: 8 protons and 9 neutrons
c. Atom Y: 9 protons and 9 neutrons
d. Atom Z: 9 protons and 10 neutrons
Which ones below are isotopes of each other and why?
element z are isotopes because number of netron are different and number of protons are same
Compounds are made from the atoms of two or more______?
Answer:
elements
not really an explanation
A dog playing fetch starts at rest and accelerates at 4.5m/s2 north. It takes the dog 7 seconds to catch the ball. What was the speed of the dog when he caught the ball?
Answer:
31.5m/s
Explanation:
Given the following
acceleration a = 4.5m/s²
Time t= 7secs
Required
Final speed v = ?
Using the equation of motion
v = u+at
v = 0+4.5(7)
v = 31.5m/s
Hence the speed of the dog is 31.5m/s
320 joules of work were done by a force of 80 newtons. Over what
distance was the force applied?
44m
80m
4m
40m
Answer:
[tex]4\:\mathrm{m}[/tex]
Explanation:
The formula for work is given as [tex]W=F\Delta x[/tex] where [tex]F[/tex] is force applied and [tex]\Delta x[/tex] is displacement.
Rearranging this equation, we have:
[tex]\Delta x=\frac{W}{F}[/tex].
Plugging in given values, we get:
[tex]\Delta x=\frac{W}{F}=\frac{320}{80}=\fbox{$4\:\mathrm{m}$}[/tex].
Answer:
The answer is 4m
Explanation:
hope this helps!
Gamma radiation is composed of neutrons and protons.
A. True
B. False
Answer:
false
Explanation:
Answer:
The answer is B false
Explanation:
Gamma radiation is not composed of both neutrons and protons.
A hiker walks 5.0 kilometers due north for twenty minutes. He turns due west and travels 12 kilometers in 60 more minutes. Then he walks 7.0 kilometers due north in forty minutes. What is the average speed of the hiker when traveling north?
Answer:
The hikers average speed due north is 0.2 km per minute.
Explanation:
Speed is the ratio of distance moved by a body to the time taken.
i.e speed = [tex]\frac{distance}{time}[/tex]
Since the hiker walks due north and due west, then his average speed due north can be determined by;
Average speed = [tex]\frac{total distance due north}{total time taken}[/tex]
Total distance due north = 5.0 + 7.0
= 12.0 km
Total time taken = 20 + 40
= 60 minutes
= 1 hour
Average speed due north= [tex]\frac{12}{60}[/tex]
= [tex]\frac{1}{5}[/tex]
= 0.2
Average speed due north = 0.2 km/minute
The hikers average speed due north is 0.2 km per minute.
1) Which of the following is not a type of energy?
A: Thermal
B: Potential
C: Kinetic
D: Frictional
A cart falls from a track with an acceleration of 10 m/s2 (which is always the acceleration due to gravity). If it falls for 9 seconds before hitting the ground, what is it’s velocity at impact? (show work plz)
Answer:
90m/s
Explanation:
Given parameters:
Acceleration = 10m/s²
Time of fall = 9s
Unknown:
Final velocity = ?
Solution:
We can assume that the cart falls from rest.
Initial velocity = 0m/s
Using
v = u + gt
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
t is the time
v = 0 + 10 x 9 = 90m/s
Answer:
90m/s
Explanation:
Which statement about plant and animal cells is true?
A. Both have a cell wall to give them support.
B. Both have a large vacuole to store water.
C. Both use mitochondria to release energy.
D. Both use chloroplasts to store energy.
Answer:
C. Both use mitochondria to release energy
Explanation:
Plant cells have a cell wall, a large vacuole and chloroplasts but animal cells do not.
Derive Isothermal process through ideal gas.( derive it numerically)
Explanation:
Hope it helps..........
Jack and Jill decide to run a race. Jack weighs 90 kg and Jill weighs 50 kg. At the end of the race it was decided that Jack and Jill tied so they had the same speed. Which person had more momentum ?
Answer: Jack.
Explanation:
Momentum is defined as the quantity of motion.
For an object that has a mass M, and a velocity V, the momentum is written as:
P = M*V
For this problem, we know that Jack and Jill had the same speed (so they had the same velocity), let's say that this velocity is v.
Then the momentum of Jack will be:
P = 90kg*v
And the momentum of Jill will be:
P = 50kg*v
We can see that Jack will have a larger momentum, and this is because he has a larger mass than Jill, but the same velocity as her.
a) Las siglas M. RU significan
Answer:
Ver la explicación a continuación.
Explanation:
En física estas siglas significan movimiento rectilíneo uniforme, es decir es el tipo de movimiento donde la velocidad es constante. La velocidad no cambia con el tiempo.
Este tipo de movimiento se puede describir con la siguiente ecuación.
[tex]x=x_{0}+v*t[/tex]
Donde:
x = posición final [m]
xo = posición inicial [m]
v = velocidad [m/s]
t = tiempo [s]
PLEASE ANSWER ILL GIVE YOU BRAIN!!!!
Answer:
I think the first two one is 70 the second on is 14
I hope this helps if I’m wrong I’m sorry
Explanation:
HELP ME ASAP PLZZ
Which of the following is not a measurement taken by a radiosonde?
a. atmospheric composition
b. atmospheric pressure
c. wind speed
d. wind direction
Answer:
A atmospheric composition
A 5.0 kg chunk of putty moving at 10m/s collides and sticks to a 7.0 kg bowling ball that is initially at rest.What is the total momentum of the bowling ball and the putty after they collide?
Answer:
Total momentum = 50kgm/s
Explanation:
Given the following data;
Mass, M1 = 5kg
Mass, M2 = 7kg
Velocity, V1 = 10m/s
Velocity, V2 = 0m/s (since it's at rest).
To find the total momentum;
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
[tex] Momentum = Mass * Velocity [/tex]
The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.
Total momentum = M1V1 + M2V2
Substituting into the equation, we have;
Total momentum = 5*10 + 7*0
Total momentum = 50 + 0
Total momentum = 50 kgm/s
Therefore, the total momentum of the bowling ball and the putty after they collide is 50 kgm/s.
I need the answers ASAP.
Answer:
Explanation:
A) Large: As she opens her parachute, she begins to displace a large volume of air. This leads to a Large air resistance
B) increase, weight: As she falls, the air resistance force increases. Now there is a force acting in opposite directions to her weight.
C)Weight, Decelerate: The skydiver has only the downward force of her weight pulling down on her, so she starts to decelerate
D) Weight, Upward, Resultant:
Her weight is now equal to the upward force from the ground. Her resultant force is then zero
E) Increases, same, constant, resultant, terminal:
As she accelerates faster, the air resistance force increases. It is now the same as her weight. She now moves at a constant speed because the resultant force acting on her is zero. She is now at her terminal velocity.
F) Increases, same, constant, terminal:
As she decelerates, the air resistance force on her parachute increases until it is the same as her weight. She is now moving with a constant speed until she hits the ground - a new slower terminal velocity
someone please help with this
Answer:
The new force is 2/3 of the original force
Explanation:
Coulomb's Law
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:
[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]
Where:
[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]
q1, q2 = the objects' charge
d= The distance between the objects
Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:
[tex]\displaystyle F'=k\frac{2q_1*q_2/3}{d^2}[/tex]
Factoring out 2/3:
[tex]\displaystyle F'=\frac{2}{3}k\frac{q_1*q_2}{d^2}[/tex]
Substituting the original force:
[tex]F'=\frac{2}{3}F[/tex]
The new force is 2/3 of the original force
Un automobil pleacă din Alexandria la ora 23 și 25 de minute și ajunge la București la ora 0 și 20 de minute. Aflați durata mișcării. Dacă automobilul s-a deplasat cu viteza de 90 km/h, aflați distanța dintre localități.
Answer:
[tex]55\ \text{minut}[/tex]
[tex]82.5\ \text{km}[/tex]
Explanation:
Timpul când mașina părăsește Alexandria este [tex]23:25[/tex]
Ora sosirii mașinii la București este [tex]00:20[/tex]
Deci, timpul necesar pentru călătorie este [tex]60-25+20=55\ \text{minut}=\dfrac{55}{60}\ \text{ore}[/tex]
Viteza mașinii este de 90 km/h
Distanța este dată de produsul vitezei și al timpului
[tex]90\times \dfrac{55}{60}=82.5\ \text{km}[/tex]
Distanța dintre localități este [tex]82.5\ \text{km}[/tex].
What is the gravitational force of attraction between a 55 kg boy and a 40 kg girl if they are 0.10 meters apart?
Answer:
[tex]1.5\cdot 10^{-5}\:\mathrm{N}[/tex]
Explanation:
Newton's Law of Gravitation is given as:
[tex]F=G\frac{m_1m_2}{r^2}[/tex], where [tex]G[/tex] is gravitational constant [tex]6.67\cdot 10^{-11}[/tex] and [tex]r[/tex] is the distance between their centers of mass.
Therefore, the gravitational force between them is:
[tex]F=6.67\cdot 10^{-11}\frac{55\cdot40}{0.1^2}= \fbox{$1.5\cdot 10^{-5}\:\mathrm{N}$}[/tex] (two significant figures).
Rosa wants to determine how long it will take her to drive from her house to her grandmother’s house 20km away. Her average speed is 10km/hr. What formula do you use?
A. S=D/T
B. D=SxT
C. T=D/S
D. T=S/D
Answer:
C, T=D/S
Explanation:
Find the work done by a man who is pulling a box of 45kg of mass by means of rope which makes angle of 45 degrees.
Answer:
0
Explanation:
Since no distance is given, the force is not doing any work
No work is done by the man since we do not know the distance or displacement.
Work is only said to be done when the force applied on an object moves it through a particular distance.
Work done = Force x distance.
Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.
As a pendulum moves closer to the equilibrium position, how do the velocity, acceleration, and force change? The velocity decreases, the acceleration decreases, and the net force decreases. The velocity increases, the acceleration decreases, and the net force decreases. The velocity increases, the acceleration increases, and the net force decreases. The velocity decreases, the acceleration increases, and the net force increases.
Answer:
The velocity increases, the acceleration decreases, and the net force decreases.
Explanation:
Velocity is at maximum when acceleration is zero thus as the pendulum moves closer to equilibrium position, velocity increases and acceleration decreases. As the pendulum moves closer to equilibrium, the magnitude of force decreases until it reaches the equilibrium position when the magnitude of force is zero. This means the net force decreases in the same manner the acceleration decreases because from the formula of force which is the product of mass and acceleration.
Answer:
B
Explanation:
on edge
A 1.0-kilogram rubber ball traveling east at 4.0 meters per second hits a wall and bounces back toward the west at 2.0 meters per second. Compared to the kinetic energy of the ball before it hits the wall, the kinetic energy of the ball after it bounces off the wall is
Answer:
8 J and 2 J
Explanation:
Given that,
Mass of the rubber ball, m = 1 kg
Initial speed of the rubber ball, u = 4 m/s (in east)
Final speed of the rubber ball, v = -2 m/s (in west)
We need to find the kinetic energy of the ball before it hits the wall, the kinetic energy of the ball after it bounces off the wall.
Initial kinetic energy,
[tex]K_i=\dfrac{1}{2}mv^2\\\\K_i=\dfrac{1}{2}\times 1\times (4)^2\\\\K_i=8\ J[/tex]
Final kinetic energy,
[tex]K_f=\dfrac{1}{2}mv^2\\\\K_f=\dfrac{1}{2}\times 1\times (2)^2\\\\K_f=2\ J[/tex]
So, the initial kinetic energy is 8 J and the final kinetic energy is 2 J.
The kinetic energy of the ball after it bounces off the wall is 2.0 Joules.
The kinetic energy of an object is the energy that is in motion or performing work. It can be expressed by using the formula:
[tex]\mathbf{K.E = \dfrac{1}{2}mv^2}[/tex]
The mass of the object(rubber ball) = 1.0 kgThe initial speed of the rubber ball before the collision = 4.0 m/sThe final speed of the rubber ball after the collision = - 2.0 m/sThe Kinetic energy of the ball after the collision and when it bounces off the wall is computed as:
[tex]\mathbf{K.E = \dfrac{1}{2} \times 1 \times 2.0^2}[/tex]
K.E = 2.0 Joules
Learn more about kinetic energy here:
https://brainly.com/question/8101588
Please help i don't get it.
Which image matches the Topographic Map Shown?
Also, please explain how your answer is the correct answer. Why is your answer correct?
Answer:
the answer is 4
Explanation:
the picture matches eachother that's why I picked 4
Answer:
devils tower
Explanation:
on the topographic map the circular lines stop at at certain point because the moutain doesnt get any pointyer if you know what that means
in other words if the map continued with the circular lines all the way to the centerit would have been that snowny mountain
find not true when the water freezes...
Answer: i think its c
Explanation:
Answer:
a
Explanation: