The force between charged objects decreases when their separation ..... A)increase B)decrease

A marble is dropped from rest and falls for 2.3 seconds. Find its final velocity.

juin [17]

Answer:

23 m/s downward

__________________________________________________________

Taking the downward direction as positive

We are given:

Initial velocity of the marble (u) = 0 m/s

Time interval (t) = 2.3 seconds

Final velocity (v) = x m/s

Solving for the Final velocity:

Acceleration of the Marble:

We know that gravity will make the marble accelerate at a constant acceleration of 10 m/s

Final velocity:

v = u + at [First equation of motion]

x = 0 + (10)(2.3) [replacing the given values]

x = 23 m/s

Hence, after 2.3 seconds, the marble will move at a velocity of 23 m/s in the downward direction

4 0

2 years ago

Since the coefficient of friction is less than 1, what does that mean about the normal force and the force of friction?

ludmilkaskok [199]

Answer:

there is friction between the two things

Explanation:

7 0

2 years ago

An oscillator consists of a block attached to a spring (k = 427 N/m). At some time t, the position (measured from the system's e

White raven [17]

Answer:

a) 4.49Hz

b) 0.536kg

c) 2.57s

Explanation:

This problem can be solved by using the equation for he position and velocity of an object in a mass-string system:

$x=Acos(\omega t)\\\\v=-\omega Asin(\omega t)\\\\a=-\omega^2Acos(\omega t)$

for some time t you have:

x=0.134m

v=-12.1m/s

a=-107m/s^2

If you divide the first equation and the third equation, you can calculate w:

$\frac{x}{a}=\frac{Acos(\omega t)}{-\omega^2 Acos(\omega t)}\\\\\omega=\sqrt{-\frac{a}{x}}=\sqrt{-\frac{-107m/s^2}{0.134m}}=28.25\frac{rad}{s}$

with this value you can compute the frequency:

a)

$f=\frac{\omega}{2\pi}=\frac{28.25rad/s}{2\pi}=4.49Hz$

b)

the mass of the block is given by the formula:

$f=\frac{1}{2\pi}\sqrt{\frac{k}{m}}\\\\m=\frac{k}{4\pi^2f^2}=\frac{427N/m}{(4\pi^2)(4.49Hz)^2}=0.536kg$

c) to find the amplitude of the motion you need to know the time t. This can computed by dividing the equation for v with the equation for x and taking the arctan:

$\frac{v}{x}=-\omega tan(\omega t)\\\\t=\frac{1}{\omega}arctan(-\frac{v}{x\omega })=\frac{1}{28.25rad/s}arctan(-\frac{-12.1m/s}{(0.134m)(28.25rad/s)})=2.57s$

Finally, the amplitude is:

$x=Acos(\omega t)\\\\A=\frac{0.134m}{cos(28.25rad/s*2.57s )}=0.45m$

5 0

2 years ago

A cannonball is fired at a 45.0° angle and an initial velocity of 670 m/s. Assume no air resistance. What is the vertical compon

elixir [45]

Answer:

Explanation:

Given the initial velocity U = 670m/s

Horizontal velocity Ux = Ucos theta

Vertical component of the cannon velocity Uy = Usin theta

Given

U = 670m/s

theta = 45°

horizontal component of the cannonball’s velocity = 670 cos 45

horizontal component of the cannonball’s velocity = 670(0.7071)

horizontal component of the cannonball’s velocity = 473.757m/s

Vertical component of the cannonball’s velocity = 670 sin 45

Vertical component of the cannonball’s velocity = 670 (0.7071)

Vertical component of the cannonball’s velocity = 473.757m/s

Hence pair of answer is 473.8 m/s; 473.8 m/s

6 0

2 years ago

A protein molecule in an electrophoresis gel has a negative charge. The exact charge depends on the pH of the solution, but 30 e

Reika [66]

Answer:

7.401 * 10^(-15) N

Explanation:

30 electrons will have a charge:

30 * -1.6022 * 10^(-19) C

= - 4.806 * 10^(-18) C

The relationship between electric field and electric force is:

E = F/q

This means that force, F, is

|F| = |E|*|q|

|F| = |1540| * |-4.806 * 10^(-18)|

|F| = |-7401.24 * 10^(-18)|

|F| = 7.401 * 10^(-15) N

7 0

3 years ago