When you look at the backside of a shiny teaspoon held at arm's length, do you see yourself upright or upside down? (b) When you look at the other side of the spoon, do you see yourself upright or upside down? Assume in both cases that the distance between you and the spoon is greater than the focal length of the spoon.
Answer:
a) The back spoon gives a right image (upright)
b) the front gives an inverted image
Explanation:
The spoon is a curved metallic object, when we see ourselves from the back we have a convex mirror, in this type of mirror when the law of reflection is applied the rays diverge therefore the eye-brain system forms the image with the prolongation of the rays, therefore the image is straight and smaller than the object.
When we look through the deep side of the spoon, we have a concave mirror and as the object (we) is further away than the distance, the rays converge to a point, so the image is real, inverted smaller than the object.
In summary.
a) The back spoon gives a right image (upright)
b) the front gives an inverted image
explain the refraction of light on a glass slab
Answer:
refraction is the change in direction of a wave passing from one medium to another or from a gradual change in the medium.
A dog runs 51 m west to fetch a ball and brings it back only 27 m before stopping.
The total displacement of the dog is:
A go-cart is traveling at 15 mi/hr. How long does it take the go-cart to travel 3 miles?
Answer:
12 min
Explanation:every 4 minutes is 1 mile
(Need help pls)!!!!!
Answer:
I assume they want answer A, but it's a silly question.
Explanation:
Well, if we assume that the girls are applying equal force, as they are the same size and strength (apparently also the same resolve etc.).
Equal force in opposite directions means the composite force is null. An object that no force is applied to continues moving in the same direction, so if the doll was moving somewhere, it would keep doing so, except all of this makes no sense the doll is not in gravityless vacuum what are we even talking about.
The answer A is the least ridiculous.
types of wave interactions include
The Brazilian rain forest is an area with significant biodiversity. As the rain forest is replaced with agricultural land, it is reasonable to predict a reduction in -
Answers-
A: consumption of solar energy.
B: sustainability over time.
C: precipitation levels.
D: average daily temperature.
Answer:
Bb
Explanation:
A bird travels at a speed of 14.2 m/s for 514 meters. How many seconds did it
fly?
Answer:
0.54 sec
Explanation:
Answer:
Time = 36.19 secondsExplanation:
Speed = 14.2 m/s
Distance = 514 m
Time = Distance / Speed
Time = 514 / 14.2
Time = 36.19 seconds
a 7 kg object moving 10 m/s Right collides with a 14 kg object at rest. If after the collision the 7kg object is at rest and the 14 kg object is moving, what is the velocity of the 14 kg object after the collision?
Answer:
v2(final)=5 m/s
Explanation:
we are going to use the conservation of momentum here
m1*v1(initial)+m2*v2(initial)=m1*v1(final)+m2v2(final)
m1=7 kg v1(initial)=10 m/s
m2=14 kg v2(initial)=0 m/s (bc initially it is at rest)
v1(final)= 0 m/s (m1 stops moving after the collision)
v2(final)=?
7*10+14*0=7*0+14*v2(final)
70=14v2(final)
v2(final)=70/14 m/s=5 m/s
A 0.70-kg disk with a rotational inertia given by MR 2/2 is free to rotate on a fixed horizontal axis suspended from the ceiling. A string is wrapped around the disk and a 2.0-kg mass hangs from the free end. If the string does not slip then as the mass falls and the cylinder rotates the suspension holding the cylinder pulls up on the mass with a force of______
Answer:
The force will be "9.8 N".
Explanation:
The given values are:
mass,
m = 0.7 kg
M = 2
g = 9.8
Now,
⇒ [tex]\tau = T \alpha[/tex]
then,
⇒ [tex]\frac{1}{2}mR^2(\frac{1}{R}\frac{dv}{dt}) =M(g-a_t)R[/tex]
⇒ [tex]\frac{1}{2}m \ a_t=m(g-a_t)[/tex]
⇒ [tex]a_t=\frac{2g}{(\frac{m}{M} +2)}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{2\times 9.8}{\frac{0.7}{2} +2}[/tex]
⇒ [tex]=8.34 \ m/s[/tex]
hence,
⇒ [tex]T=mg+M(g-a_t)[/tex]
On substituting the values, we get
⇒ [tex]=0.7\times 9.8+2(9.8-8.34)[/tex]
⇒ [tex]=6.86+2(1.46)[/tex]
⇒ [tex]=6.86+2.92[/tex]
⇒ [tex]=9.8 \ N[/tex]
If a 75 W lightbulb is 15% efficient, how many joules of light energy does the bulb produce every minute?
Answer:
1 W = 1 J / sec Definition of watt is 1 joule / sec
So if a bulb uses 75 J / sec it must use
75 J/s * 60 sec / min = 4500 J/min energy used by bulb
If bulb is 15% efficient then the light delivered is
P = 4500 J / min * .15 = 675 J / min
Please solve for 15 points. Please don’t input a link.
Answer:
a). Single replacement.
Explanation:
Because one element replaces another element in a compound
6. The rate at which velocity changes is called
O speed
O direction
O acceleration
O displacement
If an athlete runs the triathlon of 10 km in 2 hours, what is her average speed in kilometers per hour?
Answer: 5 km per hour
Explanation:
if in 10 km there is 2 hours, then 10 divided by 2 is 5.
A uniform magnetic field is in the positive z direction. A positively charged particle is moving in the positive x direction through the field. The net force on the particle can be made zero by applying an electric field in what direction
Answer:
We apply an electric field in the negative y direction
Explanation:
Since A uniform magnetic field is in the positive z direction and A positively charged particle is moving in the positive x direction through the field, the magnetic force acting on the positively charged particle is in the positive y direction according to Fleming's right-hand rule.
For the net force on the particle to be zero, we apply an electric field in the negative y direction to create an electric force on the positively charged particle, so as to cancel out the magnetic force.
a disk of a radius 50 cm rotates at a constant rate of 100 rpm. what distance in meters will a point on the outside rim travel during 30 seconds of rotation?
Answer:
Wait lang po sandali po wait lang
Which of these cubes absorb the most light?
Answera black cube or dark colors cause dark colors suck in heat
a train has an initial velocity of 30 m/s. If the train accelerates uniformly at a rate of 6.3 m/s ^ for 2.8 seconds what is the trains final velocity?
T
Answer:
the velocity is a second final to initial velocity of 39
A person applies a constant force of 100 N on an object of mass 20 kg. The object moves horizontally at a constant speed of 0.20 m/s through a distance of 0.80 m. What is the net work done on the object
Answer:
the net work done on the object is 80 J.
Explanation:
Given;
force applied on the object, F = 100 N
mass of the object, m = 20 kg
speed of the object, v = 0.2 m/s
distance moved by the object, d = 0.8 m
The net work done on the object is calculated as follows;
W = F x d
W = 100 N x 0.8 m
W = 80 J
Therefore, the net work done on the object is 80 J.
Daryl ties a rope to a brick and lifts the brick straight up. The free-body
diagram below shows the brick when it is suspended above the ground.
Force 1
Force 2
What is force 1 in this diagram?
O A. Friction
OB. Tension
O C. Normal force
O D. Weight
The force 1 is tension force.
To find the correct statement among all the options, we need to know more about friction, tension, normal force and weight.
What is friction?Friction force is found between two surfaces when one is kept or moved on another surface.It is directed opposite to the direction of motion.What is tension force?When any object is hanged by an thread or rope, that object exerts a force on that rope. This force is called as tensional force.It's directed from along the rope towards the point of hanging.What is normal force?When an object is kept on a surface, the surface exerts a force on the object to oppose the weight of the object which is the normal force.It's perpendicular to the surface that an object contacts.What is weight?Weight is the gravitational force exerted by earth on that object. It's always directed towards the center of the earth.Thus, we can conclude that the correct option is (B).
Learn more about tension here:
https://brainly.com/question/2008782
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if the density of a napthalene ball is 0.02kg.what is the mass of the napthalene ball if it has a volume of 100m³
volcano has both useful and harmful effects give reason
Answer:
harmful effects
1. that will cause air pollution
2. that will destroy our earth
Answer:
useful effects of volcano are :-
it makes soil fertile it provides valuable nutrients for the soilharmful effects of volcano are:-
it makes air polluted it destroy the environment .hope it is helpful to you ☺️
I’ll mark you as brinlist please help.
Answer:
245 divided by 5.14=47.6653696 or 47.66
Explanation:
Water can form large dewdrops in nature how would droplets made of isopropyl alcohol instead of water be different
Answer:
isopropyl alcohol would form smaller droplets, because it has lower surface tension than water has
Explanation:
Ap3x
The droplets made of isopropyl alcohol instead of water be smaller due to surface tension.
What is droplets?The single drop of a liquid in the form of sphere is called droplet.
Water can form large dewdrops in nature. Isopropyl alcohol would form smaller droplets, because it has lower surface tension than water.
Surface tension is the property of the liquid to acquire minimum surface area.
Thus, droplets made of isopropyl alcohol instead of water be smaller.
Learn more about droplet.
https://brainly.com/question/2926487
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When a car makes a sharp left turn, what causes the passengers to move toward the right side of the car? *
A centrifugal force
B inertia
C centripetal acceleration
D centripetal force
B, the body at rest becomes reluctant to start moving or a body in motion becomes
reluctant and stop moving once in motion in a straight line
An object, with mass 64 kg and speed 14 m/s relative to an observer, explodes into two pieces, one 2 times as massive as the other; the explosion takes place in deep space. The less massive piece stops relative to the observer. How much kinetic energy is added to the system during the explosion, as measured in the observer's reference frame
Answer:
K_f = 1881.6 J
Explanation:
To solve this exercise, let's start by finding the velocities of the bodies.
We define a system formed by the initial object and its parts, with this the forces during the explosion are internal and the moment is conserved
initial instant. Before the explosion
p₀ = M v₀
final instant. After the explosion
p_f = m₁ v + m₂ 0
the moeoto is preserved
p₀ = p_f
M v₀ = m₁ v
v = [tex]\frac{m_1}{M}[/tex] v₀
in the exercise they indicate that the most massive part has twice the other part
M = m₁ + m₂
M = 2m₂ + m₂ = 3 m₂
m₂ = M / 3
so the most massive part is worth
m₁ = 2 M / 3
we substitute
v = ⅔ v₀
with the speed of each element we can look for the kinetic energy
initial
K₀ = ½ M v₀²
Final
K_f = ½ m₁ v² + 0
K_f = ½ (⅔ M) (⅔ v₀)²
K_f = [tex]\frac{8}{27}[/tex] (½ M v₀²)
K_f = [tex]\frac{8}{27}[/tex] K₀
the energy added to the system is
ΔK = Kf -K₀
ΔK = (8/27 - 1) K₀
ΔK = -0.7 K₀
K_f = K₀ + ΔK
K_f = K₀ (1 -0.7)
K_f = 0.3 K₀
let's calculate
K_f = 0.3 (½ 64 14²)
K_f = 1881.6 J
Acellus
What are harmful substances in the air,
soil, and water called?
A. pollutants
B. toxins
C. carcinogens
D. mutants
Which runner finished the 100 m race in the least amount of time?
Ming
Which runner stopped running for a few seconds during the race?
At what distance did Anastasia overtake Chloe in the race?
1: Ming
2: Chloe
3: 40m
A mass MM uniform solid cylinder of radius RR and a mass MM thin uniform spherical shell of radius RR roll without slipping. If both objects have the same kinetic energy, what is the ratio of the speed of the cylinder to the speed of the spherical shell
Answer:
vcyl / vsph = 1.05
Explanation:
The kinetic energy of a rolling object can be expressed as the sum of a translational kinetic energy plus a rotational kinetic energy.The traslational part can be written as follows:[tex]K_{trans} = \frac{1}{2}* M* v_{cm} ^{2} (1)[/tex]
The rotational part can be expressed as follows:[tex]K_{rot} = \frac{1}{2}* I* \omega ^{2} (2)[/tex]
where I = moment of Inertia regarding the axis of rotation.ω = angular speed of the rotating object.If the object has a radius R, and it rolls without slipping, there is a fixed relationship between the linear and angular speed, as follows:[tex]v = \omega * R (3)[/tex]
For a solid cylinder, I = M*R²/2 (4)Replacing (3) and (4) in (2), we get:[tex]K_{rot} = \frac{1}{2}* \frac{1}{2} M*R^{2} * \frac{v_{cmc} ^{2}}{R^{2}} = \frac{1}{4}* M* v_{cmc}^{2} (5)[/tex]
Adding (5) and (1), we get the total kinetic energy for the solid cylinder, as follows:[tex]K_{cyl} = \frac{1}{2}* M* v_{cmc} ^{2} +\frac{1}{4}* M* v_{cmc}^{2} = \frac{3}{4}* M* v_{cmc} ^{2} (6)[/tex]
Repeating the same steps for the spherical shell:[tex]I_{sph} = \frac{2}{3} * M* R^{2} (7)[/tex]
[tex]K_{rot} = \frac{1}{2}* \frac{2}{3} M*R^{2} * \frac{v_{cms} ^{2}}{R^{2}} = \frac{1}{3}* M* v_{cms}^{2} (8)[/tex]
[tex]K_{sph} = \frac{1}{2}* M* v_{cms} ^{2} +\frac{1}{3}* M* v_{cms}^{2} = \frac{5}{6}* M* v_{cms} ^{2} (9)[/tex]
Since we know that both masses are equal each other, we can simplify (6) and (9), cancelling both masses out.And since we also know that both objects have the same kinetic energy, this means that (6) are (9) are equal each other.Rearranging, and taking square roots on both sides, we get:[tex]\frac{v_{cmc}}{v_{cms}} =\sqrt{\frac{10}{9} } = 1.05 (10)[/tex]
This means that the solid cylinder is 5% faster than the spherical shell, which is due to the larger moment of inertia for the shell.In a nuclear fusion reaction, atoms:
split apart.
combine.
explode.
cool down.