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2 years ago

If force and displacement are in opposite directions, will work be positive or negative?

Physics

1 answer:

eimsori [14]2 years ago

8 0

It would be negative regardless of what you define as a positive direction.

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Force F acts between a pair of charges, q1 and q2, separated by a distance d. For each of the statements, use the drop-down menu

lora16 [44]

The initial force between the two charges is given by:

$F=k \frac{q_1 q_2}{d^2}$

where k is the Coulomb's constant, q1 and q2 the two charges, d their separation. Let's analyze now the other situations:

1. F

In this case, q1 is halved, q2 is doubled, but the distance between the charges remains d.

So, we have:

$q_1' = \frac{q_1}{2}\\q_2' = 2 q_2\\d' = d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{(\frac{q_1}{2})(2q_2)}{d^2}=k \frac{q_1 q_2}{d^2}=F$

So the force has not changed.

2. F/4

In this case, q1 and q2 are unchanged. The distance between the charges is doubled to 2d.

So, we have:

$q_1' = q_1\\q_2' = q_2\\d' = 2d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{q_1 q_2)}{(2d)^2}=\frac{1}{4} k \frac{q_1 q_2}{d^2}=\frac{F}{4}$

So the force has decreased by a factor 4.

3. 6F

In this case, q1 is doubled and q2 is tripled. The distance between the charges remains d.

So, we have:

$q_1' = 2 q_1\\q_2' = 3 q_2\\d' = d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{(2 q_1)(3 q_2)}{d^2}=6 k \frac{q_1 q_2}{d^2}=6F$

So the force has increased by a factor 6.

8 0

2 years ago

Read 2 more answers

football player A has a mass of 110 kg is running on the field is velocity of 2 m/s football player B has a mass of 120 kg and a

valkas [14]

Complete Question:

Football player A has a mass of 110 kg, and he is running down the field with a velocity of 2 m/s. Football player B has a mass of 120 kg and is stationary. What is the total momentum after the collision?

Answer:

Total momentum = 220 Kgm/s.

Explanation:

<u>Given the following data;</u>

For footballer A

Mass, M1 = 110kg

Velocity, V1 = 2m/s

For footballer B

Mass, M1 = 120kg

Velocity, V1 = 0m/s since he's stationary.

To find the total momentum;

Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.

Mathematically, momentum is given by the formula;

$Momentum = mass * velocity$

a. To find the momentum of A;

$Momentum \; A = 110 * 2$

Momentum A = 220 Kgm/s.

b. To find the momentum of B;

$Momentum \; B = 120 * 0$

Momentum B = 0 Kgm/s.

c. To find the total momentum of the two persons;

$Total \; momentum = Momentum \; A + Momentum \; B$

Substituting into the equation, we have;

$Total \; momentum = 220 + 0$

<em>Total momentum = 220 Kgm/s. </em>

7 0

2 years ago

A 15.0 m long steel rod expands when its temperature rises from 34.0 degrees C to 50.0 degrees C. What is the change in the beam

azamat

0.00288................

8 0

3 years ago

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In what way would a digital thermometer be preferable to those from a liquid-based thermometer?

garik1379 [7]

Reading a digital thermometer is more preferable because you can just easily read the measurement from a screen, a number will just show in a screen as compared to a liquid-based thermometer where you still have to read the measurement by counting the markers in the thermometer. Hope this helps! Mark brainly please!

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2 years ago

Classyfying— what is the name of the force you exert on a sponge when you squeeze it?

Kruka [31]

Its called compression

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2 years ago

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