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3 years ago

A water skier has a mass of 79.0 kg and accelerates at 1.40 m/s2. What is the net force acting on him? F = ___ N

1 answer:

5 0

The answer is 111.

Using Newton's Second Law, F=ma, plugging known values in we get:

F = (79kg)(1.4m/s^2) = 110.6N ≈ 111N

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Objects 1 and 2 attract each other with a electrostatic force of 18.0 units. If the charge

xxMikexx [17]

Answer:

new force is 6 times of the initial force.

Explanation:

Let the charges on two objects is q₁ and q₂. The electric force between charges is given by :

$F=\dfrac{kq_1q_2}{r^2}$

Objects 1 and 2 attract each other with a electrostatic force of 18.0 units

If the charge of Object 1 is doubled and the charge of object 2 is tripled, it means, $q_1'=2q_1$ and $q_2'=3q_2$ . New force is given by :

$F'=\dfrac{kq_1'q_2'}{r^2}\\\\F'=\dfrac{k(2q_1)(3q_2)}{r^2}\\\\F'=6\dfrac{kq_1q_2}{r^2}\\\\F'=6F$

So, the new electrostatic force between objects will become 6 times of the initial force.

5 0

3 years ago

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

3 years ago

If the mass of a body is 9.8kg on the earth, what would be its mass on the moon?

devlian [24]

Answer:

it will remain same because mass of the body is constant everywhere

4 0

3 years ago

Increase the slit width to 1050 nm. What happens to the width of the central bright fringe? (Always remember to wait a few secon

djyliett [7]

Answer:

Explanation:

In case of Single Slit, diffraction will occur.

Then In Single slit Diffraction, width of central fringe is

$x_c= 2D\lambda/a
$

where D= distance b/w screen and slit

a= slit width

\lambda = wavelength

Thus if Screen width increases keeping other factors same then width of central fringe becomes narrower as

$x_c\propto 1/a$

On increasing the slit width the central bright fringe width The width of the central bright fringe becomes narrower.

3 0

4 years ago

How does the time at which you see things happen at a baseball game compare to the time when you hear things happen? Explain you

hoa [83]

Answer:

Because of the speed of the sound.

Explanation:

The first thing that happens in such cases is to take into account the speed of the sound. First, we see that the player hits the ball with the bat, if we are in the stands far enough we will hear the sound of the batting time later, this time depends on the speed of the sound which is equal to 345 [m/s].

Another visible and practical example is a fireworks display, where people nearby immediately hear the explosion. while those at a great distance will be able to see first the explosion followed by the sound.

With the following equation, we can calculate how long it takes to hear a hit or explosion

t = x / v

where:

x = distance [m]

v = sound velocity = 345 [m/s]

t = time [s]

7 0

3 years ago