Light has properties of both a particle and a wave. true or false

1. when their charges are of the same signs

Explanation:

Electrostatic force is the force exerted betwen objects that have charge. The magnitude of the force is given by:

where k is the Coulomb constant, q1 and q2 are the charges of the two objects, and r is the separation between the two objects. The sign (and therefore the direction) of the force depends on the relative signs of the two charges. In fact:

- When the two charges have same sign, the force is positive, which means that it is a repulsive force

- When the two charges have opposite sign, the force is negative, which means that it is an attractive force

So, we can conclude that

Two charged objects repel each other when their charges are of the same signs

2. Two terminals, one positive and negative

Explanation:

Batteries are devices which provides (usually through some chemical reactions) a potential difference, also called electromotive force. When connected to a closed circuit, this potential difference provided by the battery "pushes" electrons through the circuit, generating an electric current.

Batteries have generally two terminals: one terminal at positive voltage, called positive terminal, and one terminal at negative voltage, called negative terminal. When connected to the circuit, electrons are pushed from the negative terminal through the circuit towards the positive terminal of the battery.

The correct answer to the question is : 10 m/s , northwest.

EXPLANATION:

As per the question, the velocity of wind V = 8 m/s towards north.

      The velocity of the paper airplane is V' = 6 m/s towards west.

We are asked to calculate the actual velocity of the airplane.

By putting Pythagorean theorem, the actual velocity of the airplane is calculated as -

                ⇒  

                ⇒  

                ⇒  

                ⇒    towards northeast.

Hence, the correct answer is 10 m/s , northwest.              

Potential energy or stored energy, and kinetic energy, the energy due to motion can be balanced in the process of converting kinetic energy to potential energy during an uphill motion

The correct option for, which situation shows potential energy and kinetic energy are balanced is option;

A roller coaster car going uphill

The reason the selected option is correct is as follows:

Potential energy is the energy that is due to the relative position of an item in relation to a ground or zero state. The formula for potential energy due to the elevation is given as follows;

Potential energy, P.E. = m·g·h

Kinetic energy is the energy that is due to motion. The kinetic energy of an item is given as follows;

Kinetic energy, K.E. = (1/2) × m × v²

The potential and kinetic energy of a body is balanced when we have;

P.E. = m·g·h = K.E. = (1/2)·m·v²

Which gives;

g·h = (1/2)·v²

Therefore, a point is reached as the an body moves up a heal, where the potential energy (the energy due to height of the object) and the kinetic energy (the energy due to current speed) of the object are equal

The correct situation which shows potential energy and kinetic energy are balanced is therefore; A roller coaster car going uphill

Learn more about potential and kinetic energy here:

brainly.com/question/18963960

Answer:

2.Reducing the friction between the wagon wheels

Explanation:

If the friction between the wagon wheels and the rail is reduced, then less force will be needed to pull the wagon up. This is because the friction force goes in the opposite direction of the movement, that is, friction force opposes the desired movement, making it more difficult.

Answer:

No, the apple will reach 4.20041 m below the tree house.

Explanation:

t = Time taken

u = Initial velocity = 2.8 m/s

v = Final velocity = 0

s = Displacement

g = Acceleration due to gravity = -9.81 m/s² = a (negative as it is going up)

Equation of motion

The height to which the apple above the point of release will reach is 0.39959 m

From the ground the distance will be 1.3+0.39959 = 1.69959 m

Distance from the tree house = 5.9-1.69959 = 4.20041 m

No, the apple will reach 4.20041 m below the tree house.

The values in the option do not reflect the answer.

Final answer:

The apple will not reach the friend in the tree house as it will only reach a height of approximately 1.527 m.

Explanation:

To determine whether the apple will reach a friend in a tree house 5.9 m above the ground, we can use the equations of motion. Since the apple is thrown vertically upward, it will experience a negative acceleration due to gravity. Using the equation h = vo*t + (1/2)*a*t^2, where h is the final height, vo is the initial velocity, a is the acceleration, and t is the time, we can calculate the time it takes for the apple to reach a height of 5.9 m. Plugging in the values, we get:

5.9 = 2.8*t + (1/2)*(-9.81)*t^2

Simplifying the equation, we have:

-4.905*t^2 + 2.8*t - 5.9 = 0

Using the quadratic formula, we can solve for t. The quadratic formula is t = (-b ± sqrt(b^2 - 4ac)) / (2a), where a = -4.905, b = 2.8, and c = -5.9.

Plugging in the values, we get:

t = (-2.8 ± sqrt(2.8^2 - 4*(-4.905)*(-5.9))) / (2*(-4.905))

After evaluating the formula, we find that the apple will take approximately 1.527 seconds to reach a height of 5.9 m. Since the apple continues to rise after reaching this height, it will not reach the friend in the tree house.