PHYSICS
HIGH SCHOOL

Answer: Thermal energy always flows spontaneously from the body that is at a higher temperature to the body that has a lower temperature.

In this case, the thermal energy flows from the hot beverage that is at the temperature t1 to the ice cube at the temperature t2 until the two reach the same temperature t3.

Where:

t1> t2

In this case, the thermal energy flows from the hot beverage that is at the temperature t1 to the ice cube at the temperature t2 until the two reach the same temperature t3.

Where:

t1> t2

HIGH SCHOOL

The acceleration of an object can be described by the equation a=2d/t^2, where a is acceleration d is the distance, and t is time. if an object accelerates at a rate of 2(m/s^2) for 10 meters what is the total time elapsed?

To calculate for the time, we use the given equation given as:

a=2d/t^2

We are given the following:

a = 2

d = 10

We can solve as follows:

a = 2d/t^2

2 = 2(10)/ t^2

t = 3.16 s

Hope this answers the question.

a=2d/t^2

We are given the following:

a = 2

d = 10

We can solve as follows:

a = 2d/t^2

2 = 2(10)/ t^2

t = 3.16 s

Hope this answers the question.

COLLEGE

A heavy meterstick has a mass of 1 kg. When the meterstick is thrown like a spear past you, you measure its momentum to be 2mv. What do you measure its length to be?

Answer:

Its length is measured to be 0.5 m

Explanation:

From theory of relativity (mass variation), we know that:

m = mo/√(1-v²/c²)

Where, m = relative mass

and, mo = rest mass

The momentum of stick while moving, will be:

P = mv

but, it is given in the form of rest mass as:

P = 2(mo)v

thus, by comparison;

2(mo)v = mv

using value of m from theory of relativity;

2(mo)v = (mo)v/√(1-v²/c²)

√(1-v²/c²) = 1/2 ______ eqn(1)

Now, for relativistic length (L), we have the formula from same theory of relativity;

L = (Lo)√(1-v²/c²)

The rest length (Lo) of meter stick is 1 m, and the remaining term on right side √(1-v²/c²), known as Lorentz Factor, can be given by eqn (1), as equal to 1/2.

Thus,

L = (1 m)(1/2)

L = 0.5 m

MIDDLE SCHOOL

Which characteristics are used to identify types of metamorphic rocks? Check all that apply. color

foliation

rock size

grain arrangement

type of rock before metamorphosis

Answer: i think foliation and type of rock before metamorphosis

Explanation:

Answer:

D

Explanation:

MIDDLE SCHOOL

f an atom has 6 valence electrons, how many electrons does it need to gain to achieve a stable electron configuration?

For an atom to achieve a stable electron configuration, it needs 8 valence electrons. Since this atom has 6 valence electrons, it needs 2 more to achieve a stable electron configuration.

8-6=2

8-6=2

COLLEGE

Three polarizing sheets are placed in a stack with the polarizing directions of the first and third perpendicular to each other. What angle should the polarizing direction of the middle sheet make with the polarizing direction of the first sheet to obtain maximum transmitted intensity when unpolarized light is incident on the stack?

Answer: c) 45°

Explanation:

Given unpolarized light with an intensity = 1o

When this unpolarized light passes through a polarizer, the intensity of light reduces to half =Io/2 and this light becomes polarized.

Afterwards, the light passes a 2nd polarizer at an angle θ from the first.

From Malus’s law:

I2 = I1 cos2 θ

I2 = cos2 θ

When the light goes through a 3rd polarizer at (90-θ) it becomes;

I3 = I2 * cos2 (90-θ)

I3 =(Io/2)*cos2 θ* cos2(90-θ)

But I2 = (Io/2)*cos2 θ*sin2 (θ) = (IO/8)* sin2 (2θ)

From Sine functions;

Sin2(2θ) = 1

Sin (2θ) = 1

2θ = arcSin 1 = 90 °

Θ = 45°

We can eliminate a) and e) because light doesn’t get through.

HIGH SCHOOL

Which item is an example of a lever? 1. scissors

2. a screw hammered in the wall

3. a flagpole

4. the slope of a hill

5. a knife

The scissors are an example of a lever

Scissors have levers on them.

COLLEGE

A ball of mass m = 4.6 kg, at one end of a string of length L= 6.6 m, rotates in a vertical circle just fast enough to prevent the string from going slack at the top of the circle. Assuming mechanical energy is conserved, calculate the speed of the ball at the bottom of the circle.

Answer:

v₂ = 17.98 m/s

Explanation:

given,

mass of ball = m = 4.6 Kg

length of string = L = 6.6 m

force acting toward the center is equal to the force exerted by centripetal acceleration

now, calculating the speed of ball at the bottom of the circlr

work done by the gravity = change in kinetic energy

v₂ = 17.98 m/s

HIGH SCHOOL

Which of the following is not important to do when you fill out your fitness log? A. Keep accurate records of your physical activities

B. Use red ink

C. Have a parent or guardian sign your log before you submit it to your teacher

D. Be honest

Apex please help me thank you

The answer is B. you generally don't need to use a certain color of ink, but as long as you are accurate, honest, and have signatures

HIGH SCHOOL

A skier has an acceleration of 2.5 m/s2. How long does it take her to come to a complete stop from a speed of 18 m/s? A. 3.4 s B. 7.2 s C. 15.5 s D. 0.14 s

The question is defective. If her acceleration is 2.5 m/s/s, then her speed is 2.5 m FASTER each second, and she will never stop.