How much acceleration does a car need if it is to go a distance of 620 ft. In a time of 20 sec while it is speeding up

Which of the following is the most appropriate description of an electric current?

Olenka [21]

Electric current is the flow of charge due to the potential difference between two terminals per unit time. It is denoted by I and its unit is amp. It can be mathematically expressed as I=Q/t.

If this isn’t what your looking for I need the options they gave you

6 0

2 years ago

An observer at the top of a 462-ft cliff measures the angle of depression from the top of the cliff to a point on the ground to

Lana71 [14]

complete question:

An observer at the top of a 462-ft cliff measures the angle of depression from the top of the cliff to a point on the ground to be 5°. What is the distance from the base of the cliff to the point on the ground? Round to the nearest foot

Answer:

a ≈ 5281 ft

Explanation:

The observer at the top of a 462 ft cliff measures the angle of depression from the top of the cliff to a point on the ground to be 5°.

The angle of depression form the top of the cliff = 5°

The 5° is outside the triangle formed . To find the angle in the triangle we have to subtract 5° from 90°. 90° - 5° = 85° Note sum of an angle on a right angle is 90°.

using SOHCAHTOA principle we can solve for the distance from the base of the cliff to the point on the ground(a)

tan 85° = opposite / adjacent

tan 85° = a / 462

cross multiply

462 × tan 85° = a

a = 11.4300523 × 462

a = 5280.66 ft

a ≈ 5281 ft

5 0

3 years ago

Resistance in wires causes which of the following to occur?

Natasha_Volkova [10]

Resistance in wires causes thermal energy. The correct answer between all the choices given is the third choice or letter C. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.

3 0

3 years ago

Read 2 more answers

Describe the quantum mechanical model of the atom and several observations which support this model.

PIT_PIT [208]

This means that we shouldn't imagine electrons as single objects going around the atom. Instead, all we know is the probability of finding an electron at a particular location. What we end up with is something called an electron cloud. An electron cloud is an area of space in which an electron is likely to be found. It's like a 3-D graph showing the probability of finding the electron at each location in space. Quantum mechanics also tells us that a particle has certain numbers (called quantum numbers) that represent its properties. Just like how materials can be hard or soft, shiny or dull, particles have numbers to describe the properties. These include a particle's orbital quantum numbers, magnetic quantum number, and its spin. No two electrons in an atom can have exactly the same quantum numbers. Orbital quantum numbers tell you what energy level the electron is in. In the Bohr model, this represents how high the orbit is above the nucleus; higher orbits have more energy. The first orbit is n=1, the second is n=2, and so on. The magnetic quantum number is just a number that represents which direction the electron is pointing. The other important quantum mechanical property, called spin, is related to the fact that electrons come in pairs. In each pair, one electron spins one way (with a spin of one half), and the other electron spins the other way (with a spin of negative one half). Two electrons with the same spin cannot exist as a pair. This might seem kind of random, but it has effects in terms of how magnetic material is. Materials that have unpaired electrons are more likely to be magnetic

7 0

3 years ago

A speed boat increases its speed uniformly from vi = 20.0 m/s to vf = 30.0 m/s in a distance of 2.00 x 10^2m. (a) Draw a coordin

pychu [463]

a) See graph in attachment

b) The suvat equation to use is $v_f^2 - v_i^2 = 2as$

c) The acceleration is $a=\frac{v_f^2-v_i^2}{2s}$

d) The acceleration is $1.25 m/s^2$

e) The time needed is 8 s

Explanation:

a)

For this part, find in attachment the diagram representing this situation.

Since we are not given any particular direction for the motion, we choose the x-direction as the direction of motion of the boat.

Then we have the following:

- The initial position of the boat is $x_i = 0$ , the origin

- The final position of the boat is $x_f = 200 m$

- The initial velocity of the boat is $v_i = 20.0 m/s$

- The final velocity of the boat is $v_f = 30.0 m/s$

Note that the arrow representing the final velocity is longer than that of the initial velocity, since the final velocity is larger.

b)

The motion of the speed boat is a uniformly accelerated motion (motion at constant acceleration), therefore we can use one of the suvat equations. In this particular problem, we know the following quantities:

$v_i = 20.0 m/s$ , the initial velocity

$v_f = 30.0 m/s$ , the final velocity

$s = x_f - x_i = 200 m$ , the displacement of the boat