I an exthermic reaction, why does the chemical reaction give off energy in the form of heat or light

Answer:

When light is reflected, the "outgoing" ray is also called the reflected ray.

Explanation:

when an light ray is incident on a boundary of two mediums it an reflect or refract.

reflected ray is the part of the ray that gets back with same mediu that it was coming from. angle of reflection and incident are equal . angle of reflection and incident are the angle made by the reflected and incident ray with the normal.

total internal reflection occurs when the incident angle is greater than the critical angle of pair of given medium and when light travels from denser to rarer medium . in total internal reflection ray gets reflected with no loss at all.

in refracted ray the the light ray passes to the other medium angle of incidence and refraction are not same.

If light refracts toward the normal when passing from water to an unknown medium, it indicates that the unknown medium has a higher index of refraction than water.

When light waves travel through water and encounter a boundary with another medium at a non-normal angle, they undergo refraction. If the medium has an index of refraction higher than that of water, the light waves slow down, bending toward the normal due to the change in speed. According to Snell's law, the path of light is dependent on the indices of refraction of the two media and the angle of incidence. In this case, if the angle of refraction is closer to the normal compared to the angle of incidence, it indicates that the unknown medium has a higher index of refraction than water.

Answer:

Kinetic energy of the girl and her bike is 5.544 kJ

Explanation:

Given that a girl is riding bike at speed of 12m/s

Also, mass of Girl is 55kg and mass of bike is 22kg

Let, Total mass of girl and bike be M=22+55=77kg

Now, Kinetic energy is given by K=[tex]\frac{1}{2} Mv^{2}[/tex]

Hence, Kinetic energy of the girl and her bike will be

K=[tex]\frac{1}{2} Mv^{2}[/tex]

K=[tex]\frac{1}{2} (77)(12)^{2}[/tex]

K=5544J

Thus, Kinetic energy of the girl and her bike is 5.544 kJ

The horizontal velocity D. remains constant throughout the fall.

Explanation:

The motion of the rock off the cliff is a projectile motion, which consists of two independent motions:

Here in this problem, we are only interested in the horizontal velocity. We said that the horizontal acceleration of the rock is zero: therefore, the horizontal velocity of the rock remains constant during the fall. (if the air drag was not negligible, then it would affect the horizontal velocity, which would decrease as the rock falls).

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Answer:

B

Explanation:

B. Edward Tolman

The psychologist known for latent learning and cognitive maps is B. Edward Tolman

The psychologist known for latent learning and cognitive maps is Edward Tolman. Tolman's various experiments with rats demonstrated that organisms can learn even if they do not receive immediate reinforcement, suggesting a cognitive aspect to comprehensive learning.

In some specific experiments, hungry rats were placed in a maze with no reward for finding their way through it. As they explored the maze, they developed a cognitive map or a mental picture of the maze layout. This is known as latent learning, which is learning that occurs but is not observable in behavior until there is a reason to demonstrate it.

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Answer:

range = x = 188 [m]

Explanation:

First we must find the velocity component on the horizontal axis or x-axis

[tex](v_{x})_{0} = 40*cos(20) \\(v_{x})_{0} = 37.58[m/s]\\[/tex]

Then using the kinematic expression that relates velocity with time, we can find the range of the projectile or the distance x.

[tex]x=(v_{x} )_{0}*t\\ x=37.58*5\\x=188[m][/tex]

The magnitude of the total momentum of the system of two cars, each with a mass of 1100 kg and moving east at 30 m/s and 15 m/s respectively, is 49500 kg·m/s east.

To calculate the total momentum of the system consisting of two cars driving east, you need to use the formula for momentum, which is the product of mass and velocity (p = mv). The momentum of each car is calculated separately and then added together since they are moving in the same direction (east).

For the first car with a mass of 1100 kg moving at 30 m/s, its momentum is:

p1 = m1 * v1 = 1100 kg * 30 m/s = 33000 kg·m/s.

For the second car with the same mass of 1100 kg but moving at 15 m/s, its momentum is:

p2 = m2 * v2 = 1100 kg * 15 m/s = 16500 kg·m/s.

The total momentum of the system is the sum of the momenta of both cars:

total p = p1 + p2 = 33000 kg·m/s + 16500 kg·m/s = 49500 kg·m/s.

Therefore, the magnitude of the total momentum of the system is 49500 kg·m/s to the east.

Answer:

volume = 0.47 [tex]m^{3}[/tex].

Explanation:

Density:

[tex]d = \frac{m}{v}[/tex]

We have that d = 2700 kg/[tex]m^{3}[/tex] and that we have 1280 kg of Al.

[tex]2700 = \frac{1280}{V}[/tex]

V = 0.47 [tex]m^{3}[/tex]

Answer:

The correct answer is 0.47 m³

Explanation:

The formula for density (d) is

Mass (m) ÷ volume (v)

Hence

d = m ÷ v

The density of aluminium (as provided in the question) is 2700  kg/m³ and the mass of aluminium is 1280 kg, the volume is however unknown.

Thus, from the formula earlier

2700 = 1280 ÷ v

v = 1280 ÷ 2700

v = 0.47 m³

The volume of aluminium when the density is 2700  kg/m³ and the mass is 1280 kg is 0.47 m³

Answer: 286.33

Explanation:

multiplay them

Answer:

KSHE [tex]94.7[/tex]

Explanation:

Given stations WIL [tex]92.3[/tex] and KSHE [tex]94.7[/tex]

The station number represents the frequency that waves of radio emit. They are measured in megahertz (MHZ).

Using the formula  

[tex]E=h\nu[/tex]

Where [tex]E[/tex] is energy.  

[tex]h[/tex] is Planck's constant.

[tex]\nu[/tex] is frequency.

We can see energy is directly related to frequency. A higher frequency will give higher energy.  

As channel KSHE [tex]94.7[/tex] has more frequency than channel WIL [tex]92.3[/tex].  

So, channel KSHE [tex]94.7[/tex] will have more energy.

1) The acceleration of the plane is 1.89 times the acceleration of gravity

2) The force acting on the airplane is [tex]2.22\cdot 10^5 N[/tex]

Explanation:

1)

The acceleration of the plane is given by

[tex]a=\frac{v-u}{t}[/tex]

where

v is the final velocity of the plane

u is the initial velocity

t is the time elapsed

For the airplane in this problem, we have:

[tex]u=0[/tex] (it starts from rest)

[tex]v=200 km/h \cdot \frac{1000 m/km}{3600 s/h}=55.6 m/s[/tex] is the final velocity

[tex]t=3 s[/tex] is the time

Substituting, we find

[tex]a=\frac{55.6-0}{3}=18.5 m/s^2[/tex]

The acceleration of gravity is

[tex]g=9.8 m/s^2[/tex]

So, the acceleration of the plane relative to [tex]g[/tex] is

[tex]\frac{a}{g}=\frac{18.5}{9.8}=1.89[/tex]

2)

The average force exerted on the plane is given by Newton's second law:

[tex]F=ma[/tex]

where

F is the force

m is the mass of the airplane

a is the acceleration

In this problem, we have

[tex]m=12000 kg[/tex] is the mass of the plane

[tex]a=18.5 m/s^2[/tex] is the acceleration

Substituting, we find:

[tex]F=(12000)(18.5)=2.22\cdot 10^5 N[/tex]

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Answer:

400 m/s

Explanation:

From the question;

We are required to calculate the speed of the wave;

Speed of the wave = 200 Hz × 2 m

                               = 400 m/s

Explanation:

For projectile motion, use constant acceleration equation:

Δx = v₀ t + ½ at²

where Δx is the displacement,

v₀ is the initial velocity,

a is the acceleration,

and t is time.

For the first object:

Δx = 60 t + ½ (-10) t²

Δx = 60 t − 5 t²

For the second object:

Δx = 0 (t−10) + ½ (-10) (t−10)²

Δx = -5 (t−10)²

When they meet, they have the same displacement, so:

60 t − 5 t² = -5 (t−10)²

60 t − 5 t² = -5 (t² − 20t + 100)

60 t − 5 t² = -5 t² + 100 t − 500

60 t = 100 t − 500

40 t = 500

t = 12.5

Plug into either of the original equations to find the displacement.

Δx = -5 (t−10)²

Δx = -5 (12.5−10)²

Δx = -31.25

The distance from the top of the cliff to the point where the objects meet is 31.25 meters.

Answer:

Overall net force is zero.

Explanation:

Given:

Susan exercise for 1 hour at constant velocity and constant speed.

So, there is no change in the velocity for 1 hour.

We know that, acceleration is the quantity that measures the change in velocity over a given time interval. If there is no change in velocity or if velocity remains constant for a given time interval, then the acceleration of the body is zero.

Now, from Newton's second law, we know that, the net force acting on a body is directly proportional to its acceleration. Therefore, for a body to experience zero acceleration means that the body will have zero net force.

Susan here exercises at constant velocity and so, her net acceleration is zero. Therefore, the overall net force acting on her will also be zero as net force is directly proportional to the acceleration.

Final answer:

In an ideal scenario ignoring external factors, the overall net force acting on Susan while she runs at a constant speed and velocity is zero, as per Newton's first law of motion.

Explanation:

The question is concerned with a scenario where Susan is running at a constant speed and velocity, implying that she is not accelerating. According to Newton's first law of motion, also known as the law of inertia, an object in motion at a constant velocity will remain in motion at that velocity unless acted upon by a net external force. Since Susan is running at a constant speed and velocity, this means there is no net external force acting on her because all forces are balanced.

Based on Newton's second law, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration (Fnet = ma), and given that Susan is not accelerating (acceleration is zero), the net force acting on her is also zero. This assumes ideal conditions where external factors like air resistance and friction are negligible or perfectly balanced by Susan’s forward force.

The distance between the two objects is 3.0 m

Explanation:

The magnitude of the gravitational force between two objects is given by the following equation:

[tex]F=G\frac{m_1 m_2}{r^2}[/tex]

where :

[tex]G=6.67\cdot 10^{-11} m^3 kg^{-1}s^{-2}[/tex] is the gravitational constant

[tex]m_1,m_2[/tex] are the masses of the two objects

r is the separation between the objects

In this problem, we have:

[tex]m_1 = 2 kg[/tex] is the mass of the book

[tex]m_2 = 5 kg[/tex] is the mass of the vase

[tex]F=7.41\cdot 10^{-11}N[/tex] is the force between the two objects

Re-arranging the equation and solving for r, we find the distance between the two objects:

[tex]r=\sqr{\frac{Gm_1 m_2}{F}}=\sqrt{\frac{(6.67\cdot 10^{-11})(2)(5)}{7.41\cdot 10^{-11}}}=3.0 m[/tex]

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Answer:

3.00 m

Explanation:

Answer:

4.4 m/s

Explanation:

Angular momentum is:

L = Iω

For a point mass, this can also be written as:

L = mvr

Angular momentum is conserved, so:

L₁ = L₂

m₁ v₁ r₁ = m₂ v₂ r₂

(2 kg) (1.1 m/s) (0.6 m) = (2 kg) v (0.15 m)

v = 4.4 m/s

Answer:

a. 60.5 kg

Explanation:

Given data,

The maximum water a boat can displace is, 60.5 ml

According to the principle of buoyancy, the weight of the floating body is equal to the weight of the liquid displaced.

Under standard temperature and pressure, a unit mass of water equals one liter.

If a boat can displace a maximum of 60.5 ml of water, then it can hold a mass of a maximum of 60.5 kg of mass.

The object that I did choose to put on the skateboard ​ is a sticky ball.

A sports scientists is said to have confirmed that skateboarding is seen to be a very goof and complete workout.

Note that  It not only functions along the cardiovascular system and it also helps to create muscular strength. The core of a skateboarder is seen as very crucial role.

The object that I did choose to put on the skateboard ​ is a sticky ball and it is one where i can measure the velocity as well as the speed taken.

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Answer:

0. 1226495726kg

Explanation:

Force is the product of mass and acceleration.

Mathematically,

Force(F) = mass (m)×acceleration(a)

Substituting the values into the equation

2. 87=m×23. 4

2. 87=m (23. 4)

2. 87/23. 4=m (23. 4)/23. 4

2. 87/23. 4=m

0. 1226495726=m

Answer:

Answer:

0. 1226495726kg

Explanation:

Force is the product of mass and acceleration.

Mathematically,

Force(F) = mass (m)×acceleration(a)

Substituting the values into the equation

2. 87=m×23. 4

2. 87=m (23. 4)

2. 87/23. 4=m (23. 4)/23. 4

2. 87/23. 4=m

0. 1226495726=m

Explanation:

Work is the amount of energy transferred

Explanation:

In physics, work is a measure of the energy transfer occurring in a process. Typically, we talk about work when energy is converted from one form into another.

For instance, work is done when a force is applied on an object. The work done on the object is given by:

[tex]W=Fd cos \theta[/tex]

where

where

F is the magnitude of the force

d is the displacement

[tex]\theta[/tex] is the angle between the direction of the force and of the displacement

We notice the following:

Whenever work is done, there is also an energy transfer taking place. For instance, in the previous example, when the force is applied to the object, the object will accelerate (assume there is no friction), and will gain kinetic energy: therefore, there is a transfer of energy to the object.

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Answer:

Direct Current

Explanation:

The electricity only flows in one direction.

Answer: 13.6 N

Explanation:

The equation of motion for the rabbit is:

[tex]\Delta x=V_{ox}t+\frac{1}{2}a_{x}t^{2}[/tex] (1)

Where:

[tex]\Delta x=0.85 m[/tex] is the distance traveled by the rabbit

[tex]V_{ox}=0 m/s[/tex] is the rabbit's initial velocity, assuming it started from rest

[tex]t=0.5 s[/tex] is the time

[tex]a_{x}[/tex] is the acceleration

Isolating [tex]a_{x}[/tex]:

[tex]a_{x}=\frac{2 \Delta x}{t^{2}}[/tex] (2)

[tex]a_{x}=\frac{2 (0.85 m)}{(0.5)^{2}}[/tex] (3)

[tex]a_{x}=6.8 m/s^{2}[/tex] (4)

On the other hand, the force [tex]F_{x}[/tex] is given by:

[tex]F_{x}=m.a_{x}[/tex] (5)

Where [tex]m=2 kg[/tex] is the mass of the rabbit

Substituting (4) in (5):

[tex]F_{x}=(2 kg)(6.8 m/s^{2})[/tex] (6)

Finally:

[tex]F_{x}=13.6 N[/tex]

Point of correction, acceleration is 9.81 m/s2

Answer:

5.4 Kg

Explanation:

We know that F=ma and making m the subject of the formula then

[tex]m=\frac {F}{a}[/tex] where m is the mass of the skateboard, F is the pulling force and a is the acceleration of the body

Substituting 53 N for F and 9.81 m/s2 for a then

[tex]m=\frac {53 N}{9.81 m/s2}=5.40265 Kg\approx 5.4 Kg[/tex]

Answer:

8100 J

Explanation:

KE = ½ mv²

KE = ½ (50 kg) (18 m/s)²

KE = 8100 J

Answer:

These 5 principles can be better understood from the past events as well as from formation of the sedimentary rocks

Explanation:

Principle of original horizontal- the sedimentary rocks are found to be horizontal during the initial deposits phase. If  tilted this is due to the subsequent geological event.

Principle of original lateral continuity- The sedimentary beds are originally laterally continuous into their environment of deposition. Faulting in the severe folding and also erosion may leads to the separation of the originally lateral continuous beds which in later becomes separate units.

Principle of cross cutting- The younger features can get cuts across the older features. That's why faults,  erosion, volcanoes etc can be seen. The above mentioned are younger than those materials that is faulted intruded, or eroded.

Principle of inclusion- Inclusion itself means (a rock fragment another rock fragment) they must be older than the materials in.

Principle of uniformity-  Those are the physical process that are been seen today, were also worked in the same way in the geologic past, thus modern methods helps us to understand the ancient events.

Answer:

Oxygen. When trees "breathe" they release oxygen and take in the carbon dioxide. On the other hand, when humans breathe we take in that oxygen and release carbon dioxide. In this way, we have a relationship that is mutually beneficial.

322.5 joules

Data given;

We are supposed to determine the amount of heat required.

In this case, specific heat, c of gold is 0.129 J/g/°C

Mass of gold in grams is 100 g

Therefore;

Q = 100 g × 0.129 J/g/°C × 25°C

   = 322.5 joules

Thus, the amount of heat required is 322.5 Joules

Answer:

Your mother can tell you that answer

Explanation:

i) The lowest temperature recorded is [tex]12^{\circ}C[/tex]

ii) All the liquid has evaporated after 140 seconds

Explanation:

i)

In this part of the problem, we have to find the lowest temperature recorded as the liquid evaporates.

In order to do that, we have to look at the graph, where we have:

- The time (in seconds) represented on the x-axis

- The temperature (in Celsius degrees) represented on the y-axis

The lowest temperature recorded corresponds to the minimum value of the variable on the y-axis. By looking at the graph, we see that the temperature starts from [tex]20^{\circ}[/tex] at time [tex]t=0[/tex], then it reaches a minimum of approximately [tex]12^{\circ}C[/tex] at about [tex]t=140 s[/tex], then it increases again. Therefore, the lowest temperature recorded is [tex]12^{\circ}C[/tex].

ii)

In this part, we have to determine how long it takes for all the liquid to evaporate.

The process of evaporation of a liquid takes place when the molecules located on the surface of the liquid, which have more kinetic energy than the other molecules, "escape" the liquid. When these molecules escape the liquid, they remove heat from the liquid (because they carry away energy): therefore, the temperature (which is a measure of the kinetic energy) at the surface of the liquid decreases. This effect is known as cooling effect of evaporation.

When this decrease in temperature stops, it means that the liquid has completely evaporated. From the graph, we see that this occurs when the time is approximately about 140 seconds.

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Answer:

non linear square relationship

Explanation:

formula for centripetal force is given as

a = mv^2/r

here a ic centripetal acceleration , m is mass of body moving in circle of radius r and v is velocity of body . If m ,and r are constant we have

a = constant × v^2

a α v^2

hence non linear square relationship

The relationship between velocity and centripetal force is a nonlinear square relationship.

The centripetal force is given by;

F = mv^2/r

The centripetal force is the force required to keep an object moving in a circular path.

If we take the relationship between the centripetal force and velocity as we can see in the equation above, we realize that it is a nonlinear square relationship. Therefore, the relationship between velocity and centripetal force is a nonlinear square relationship.

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