The current in a hair dryer measures 20.0 amps. The resistance of the hair dryer is 6 ohms. What is the voltage?

Joe is measuring the time it takes for a ball to roll down a ramp. In this experiment Joe takes the measurement 5 times and gets

PolarNik [594]

Step by step solution :

standard deviation is given by :

$\sigma = \sqrt\dfrac{{\sum (x-\bar{x})^2}}{n}$

where, $\sigma$ is standard deviation

$\bar{x}$ is mean of given data

n is number of observations

From the above data, $\bar{x}=24.88$

Now, if $x=24.8$ , then $(x-\bar{x})^2=0.0064$

If $x=23.9$ , then $(x-\bar{x})^2=0.9604$

if $x=26.1$ , then $(x-\bar{x})^2=1.4884$

If $x=25.1$ , then $(x-\bar{x})^2=0.0484$

If $x=24.5$ , then $(x-\bar{x})^2=0.1444$

so, $\sum (x-\bar{x})^2 =\frac{0.0064+0.9604+1.4884+0.0484+0.1444}{5}$

$\sum (x-\bar{x})^2 =2.648$

$\sqrt{\sum \frac{(x-\bar{x})^2}{n}}$

$\sigma =0.7277$

No, Joe's value does not agree with the accepted value of 25.9 seconds. This shows a lots of errors.

6 0

2 years ago

A compass is a magnet and Earth is a magnet. How does the magnetism of a compass work with the

Doss [256]

The compass magnet aligns itself with the earths magnetic field.

7 0

3 years ago

Suppose you want to design an air bag system that can protect the driver at a speed 100 km/h (60 mph) if the car hits a brick wa

34kurt

When solving question that contains equations and the use mathematical computations, It is always ideal to list the parameters given.

Now, given that:

the speed of the car which is the initial velocity (u) = 100 km/h before it hits the wall.
after hitting the wall, the final velocity will be (v) = 0 km/h

Assumptions:

Suppose we make an assumption that the distance travelled during the collision of the car with the brick wall (S) = 1 m
That the car's acceleration is also constant.

∴

For a motion under constant acceleration, we can apply the kinematic equation:

$\mathsf{v^2 = u^2 + 2as}$

where;

v = final velocity

u = initial velocity

a = acceleration

s = distance

From the above equation, making acceleration (a) the subject of the formula:

$\mathsf{v^2 - u^2 =2as }$

$\mathsf{a = \dfrac{v^2 - u^2 }{2s}}$

The initial velocity (u) is given in km/h, and we need to convert it to m/s as it has an effect on the unit of the acceleration.

since 1 km/h = 0.2778 m/s

100 km/h = 27.78 m/s

$\mathsf{a = \dfrac{(0)^2 - (27.78)^2 }{2(1)}}$

$\mathsf{a = \dfrac{- 771.7284 }{2}}$

a = - 385.86 m/s²

Similarly, from the kinematic equation of motion, the formula showing the relation between time, acceleration and velocity is;

v = u + at

where;

v = 0

-u = at

$\mathsf{t = \dfrac{-u}{a}}$

$\mathsf{t = \dfrac{-27.78}{-385.86}}$

t = 0.07 seconds

An airbag is designed in such a way as to prevent the driver from hitting on the steering wheel or other hard substance that could damage the part of the body. The use of the seat belt is to keep the driver in shape and in a balanced position against the expansion that occurred by the airbag during the collision on the brick wall.

Thus, we can conclude that the airbag must be inflated at 0.07 seconds faster before the collision to effectively protect the driver.

Learn more about the kinematic equation here:

brainly.com/question/11298125?referrer=searchResults

3 0

3 years ago

Acceleration is defined as the rate of change of position true or false

Svetradugi [14.3K]

Answer:

True

Explanation:

7 0

2 years ago

Read 2 more answers

So, RCF, or relative centrifugal force should be equal to RCF = <img src="https://tex.z-dn.net/?f=11%2C18%2Ar%2A%28RPM%2F1000%29

zysi [14]

After plugging all the data into the equation, the result of the relative centrifugal force (RCF) is measured in terms of g.

<h3>What is relative centrifugal force?</h3>

The relative centrifugal force (RCF) or the g force is the radial force generated by the spinning rotor as expressed relative to the earth's gravitational force.

RCF = ac/g

where;

ac is centripetal acceleration
g is acceleration due to gravity

$RCF = \frac{\omega ^2 r}{g} = 1.118\times 10^{-5} \ (RPM)^2 r = 11.18r\ (RPM/1000)^2$

where;

r is radius in cm

<h3>For example, </h3>

Find the maximum RCF of the JS-4.2 rotor can be obtained from its maximum speed (4200 rpm) and its rmax (250 mm);

$RCF = 11.18 \times 25\ cm \times (\frac{4200 \ RPM}{1000} )^2 = 4,930.3 \times g$

Thus, after plugging all the data into the equation, the result is measured in terms of g.

Learn more about relative centrifugal force here: brainly.com/question/26887699

#SPJ1

6 0

1 year ago