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3 years ago

13

A horizontal force of 90.0 N is required to push a 75kg object along a horizontal surface at a constant speed. What is the magni

tude of the force of friction. Please show your work I am having troubles.

1 answer:

Varvara68 [4.7K]3 years ago

6 0

If the object is moving at a constant speed, acceleration is 0. So:

$F = ma

F = m\times 0

F = 0$

The resultant force is 0. So the force pushing the object must be equal to the friction force acting, so

Friction = 90 N

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As a diligent physics student, you carry out physics experiments at every opportunity. At this opportunity, you carry a 1.33 m l

deff fn [24]

Answer: 62 μT

Explanation:

Given

Length of rod, l = 1.33 m

Velocity of rod, v = 3.19 m/s

Induced emf, e = 0.263*10^-3 V

Using Faraday's law, the induced emf of a rod can be gotten by the formula

e = blv where,

e = induced emf of the rod

b = magnetic field of the rod

l = length of the rod

v = velocity of the rod. On substituting, we have

0.263*10^-3 = b * 1.33 * 3.19

0.263*10^-3 = b * 4.2427

b = 0.263*10^-3 / 4.2427

b = 0.0000620 T

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8 0

3 years ago

Read 2 more answers

If the sprinter accelerates at that rate for a distance of 15 m, and then maintains the velocity he has at that point for the re

ahrayia [7]

Answer:

The time for the entire race is 11.39 sec.

Explanation:

Given that,

Distance = 15 m

Remainder distance = 100 m

Suppose A sprinter begins a race with an acceleration of 3.4 m/s².

We need to calculate the time

Using equation of motion

$s=ut+\dfrac{1}{2}at^2$

Put the value in the equation

$15=0+\dfrac{1}{2}\times3.4\times t^2$

$t^2=\dfrac{30}{3.4}$

$t=2.97\ sec$

We need to calculate the final velocity of sprinter

Using equation of motion again

$v=u+at$

Put the value into the formula

$v=0+3.4\times2.97$

$v=10.09\ m/s$

We need to calculate the distance covers by sprinter

$d=100-15=85\ m$

The sprinter need to covers only 85 m.

We need to calculate the time

Using formula of time

$t=\dfrac{d}{v}$

Put the value into the formula

$t'=\dfrac{85}{10.09}$

$t'=8.42\ sec$

We need to calculate the time for the entire race

$t''=t+t'$

Put the value into the formula

$t''=2.97+8.42$

$t''=11.39\ sec$

Hence, The time for the entire race is 11.39 sec.

4 0

3 years ago

Light in vacuum is incident on the surface of a slab of transparent material. In the vacuum the beam makes an angle of 39.9° wit

wariber [46]

Answer:

n=2.053

Explanation:

We will use Snell's Law defined as:

$n_{1}*Sin\theta_{1}=n_{2}*Sin\theta_{2}$

Where n values are indexes of refraction and $\theta$ values are the angles in each medium. For vacuum, the index of refraction in n=1. With this we have enough information to state:

$1*Sin(39.9)=n_{2}*Sin(18.2)$

Solving for $n_{2}$ yields:

$n_{2}=\frac{Sin(39.9)}{Sin(18.2)}=2.053$

Remember to use degrees for trigonometric functions instead of radians!

6 0

3 years ago

PLEASE HELP URGETNT

Angelina_Jolie [31]

Answer:

I think (d) is right answer

6 0

3 years ago

"How do changes in voltage or resistance affect current in an electric circuit?"

kicyunya [14]

We can answer the question by looking at the Ohm's law, which gives us the relationship between voltage (V), current (I) and resistance (R) of a circuit:
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equivalently, we can rewrite it as
$I= \frac{V}{R}$

by looking at the equation, we can make the following observations:
1) The current is proportional to the voltage: therefore, if the voltage increases, the current increases as well; if the voltage decreases, the current decreases too.
2) The current is inversely proportional to the resistance: if the resistance increases, the current decreases, and if the resistance decreases, the current increases.

5 0

3 years ago