What is the force when ur pulling heavy furniture that wont budge

A car initially traveling at 17.1 mph comes to rest in 9.7s what was its acceleration in this time?

ra1l [238]

Answer:

$a=-.78m/s^2$

Explanation:

Δ $v=at$

Δ $v$ is the difference in velocity before and after a given time.
$a$ is the acceleration of the object during this time.
$t$ is time

$(v_f-v_i)=at$ is another way to write this equation.

The Δ symbol represents "the difference between the initial and final values of a magnitude or vector", so Δ $v=(v_f-v_i)$

$v_f-v_i=at\\\frac{at}{t}=\frac{v_f-v_i}{t}\\a=\frac{v_f-v_i}{t}$

I rearranged this equation to solve for $a$ , but this is a step that you don't need to take, it's just good to get in the habit of doing this.
Plug in the given values. Note that our final velocity is $0$ , because the car travels until at rest.

$a=\frac{v_f-v_i}{t}\\a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}$

Our initial velocity is in mph, something not in standard units, so if not changed, you will get an incorrect answer. What you need to do is cancel out the units your prior value had using division and multiplication, and at the same time multiply and divide the correct numbers and units into your equation. Or look up a converter.

$a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}\\a=\frac{0m/s-7.6m/s}{9.7s} \\a=\frac{-7.6m/s}{9.7s}$

if you converted correctly, your answer for $v_f$ will be ≅ $7.6m/s$ .
Now divide. Notice that the units for acceleration are $m/s^2$ or meters per second, per second.

$a=\frac{-7.6m/s}{9.7s}\\a=-.78m/s^2$

Our final answer is negative because the car is slowing down. Do not square this answer as the square symbol only applies to the units, not the magnitude.

4 0

2 years ago

Read 2 more answers

What is the tangential velocity of a record player which makes 11 revolutions in 20 seconds?

Vsevolod [243]

What is the tangential velocity of a record player which makes 11 revolutions in 20 seconds? Help hello

3 0

2 years ago

A bird sitting high in a tree is an example of an object with what type of energy?

Wewaii [24]

potential energy because it has the ability to do work

*A*

7 0

3 years ago

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When placed in a ________ solution, a cell will exhibit a net loss of water. the specific process by which the water leaves the

katen-ka-za [31]

The specific process by which the water leaves the cell is called plasmolysis.

<h3>What is plasmolysis?</h3>

Plasmolysis is the process in which the cell loses the water that is present inside it because the environment of the cells produces pressure to build up inside the cell. If a cell is present in a hypertonic solution means that solvent concentration is lower in the surrounding solution, then water comes out of the cell while on the other hand, if a cell is present in a hypotonic solution in which the solvent concentration is higher in the surrounding solution, then water goes inside of the cell. The movement of liquid inside or outside of the cell occurs due to the semi-permeable membrane of the cell.

So we can conclude that the specific process by which the water leaves the cell is called plasmolysis.

Learn more about cell here: brainly.com/question/13123319

#SPJ1

7 0

1 year ago

EMF. Currents in dc transmission lines can be 100 A or more. Some people have expressed concern that the electromagnetic fields

mrs_skeptik [129]

Answer:

The magnetic field B of the transmission line is 4.5·10^(-6)T. The ratio B/Be is 0.0009% (there is no risk to human health)

Explanation:

we will consider a dc transmission line as an infinite longitudinal line in the Z-axis with a dc current of 180 A. To solve the problem we will use ampere's law. We can consider the geometry of the problem (Rotational symmetry in respect of Z-axis) than the field B is annular with center in the transmission line.

$\vec{B}(r,\varphi,z)=B(r)\vec{\varphi}$

$\displaystyle\oint_{C} \vec{B}(r)\,\vec{dl}=\mu I_c$

We will use a circular amperian curve C. Therefore:

$\displaystyle\oint_{C} \vec{B}(r)\,\vec{dl}=\int_{0}^{2\pi} B(r)\vec{\varphi}\,\vec{\varphi}rd\varphi=B(r)r\int_{0}^{2\pi} \,d\varphi=B(r)r2\pi=\mu I_c$

$B(r)=\displaystyle\frac{\mu 180A}{r2\pi}$

For a height of 8.0m (r=8m):

$B(8m)=\displaystyle\frac{\mu 180A}{8m2\pi}=4.5\cdot10^{-6}T$

Compared to the earth magnetic field:

$\displaystyle\frac{B}{B_e}\%= \frac{B}{B_e}100=0.0009\%$

6 0

2 years ago