Ask question

Ask question

All categories

3 years ago

11

The car travels 52m in 21 seconds before it comes to a complete stop after the driver applies the brakes. What was the car's ini

tial speed?

1 answer:

prisoha [69]3 years ago

5 0

Answer:

2.48 m/s

Explanation:

D=vt

52 = V 21

V= 52/21=2.47m/s

You might be interested in

The ball will oscillate along the z axis between z=dz=d and z=−dz=−d in simple harmonic motion. What will be the angular frequen

Eddi Din [679]

Answer:

$\omega = \sqrt{\dfrac{kq_0Q}{ma^3} }$

Explanation:

Additional information:

<em>The ball has charge </em> $-q_0$ <em>, and the ring has positive charge </em> $+Q$ <em> distributed uniformly along its circumference. </em>

The electric field at distance $z$ along the z-axis due to the charged ring is

$E_z= \dfrac{kQz}{(z^2+a^2)^{3/2}}.$

Therefore, the force on the ball with charge $-q_0$ is

$F=-q_oE_z$

$F=- \dfrac{kq_0Qz}{(z^2+a^2)^{3/2}}$

and according to Newton's second law

$F=ma=m\dfrac{d^2z}{dz^2}$

substituting $F$ we get:

$- \dfrac{kq_0Qz}{(z^2+a^2)^{3/2}}=m\dfrac{d^2z}{dz^2}$

rearranging we get:

$m\dfrac{d^2z}{dz^2}+ \dfrac{kq_0Qz}{(z^2+a^2)^{3/2}}=0$

Now we use the approximation that

$z^2+a^2\approx a^2$ <em>(we use this approximation instead of the original </em> $d^2+a^2\approx a^2$ <em> since </em> $z$ <em>, our assumption still holds )</em>

and get

$m\dfrac{d^2z}{dz^2}+ \dfrac{kq_0Qz}{(a^2)^{3/2}}=0$

$m\dfrac{d^2z}{dz^2}+ \dfrac{kq_0Qz}{a^{3}}=0$

Now the last equation looks like a Simple Harmonic Equation

$m\dfrac{d^2z}{dz^2}+kz=0$

where

$\omega=\sqrt{ \dfrac{k}{m} }$

is the frequency of oscillation. Applying this to our equation we get:

$m\dfrac{d^2z}{dz^2}+ \dfrac{kq_0Q}{a^{3}}z=0\\\\m=m\\\\k= \dfrac{kq_0Q}{a^{3}}$

$\boxed{\omega = \sqrt{\dfrac{kq_0Q}{ma^3} }}$

5 0

4 years ago

Pressure in the abdomen

Vilka [71]

Answer:

Uh, what? Is there more?

Explanation:

3 0

3 years ago

This scientist focused his study on planetary motion. One of his laws is the planets orbit the Sun in elliptical patterns.

Savatey [412]

I believe that since Kepler focused his studies the rotation of the planets, and the stars, that he is the one who developed the law, which is called the first law of planetary motion.

8 0

3 years ago

A vector has an x component of -27.5 units and a y component of 41.4 units. Find the magnitude and direction of this vector. mag

evablogger [386]

Answer:

a.) magnitude __49.7__ unit(s)

b.) direction __123.6°_ counterclockwise from the +x axis

Explanation:

Let Vector is v

x-component of Vector v = x = -27.5 units (minus sign indicate that x-component is along the minus x-axis )

y-component of Vector v = y = 41.4 units

Magnitude of v = ?

Direction of v = ?

To find the magnitude of the vector

v = $\sqrt{x^{2}+y^{2} }$

v = $\sqrt{-27.5^{2}+41.4^{2} }$

v = 49.7 units

To find direction

θ = tan⁻¹(y/x)

θ = tan⁻¹(41.4/-27.5)

θ = -56.4°

This Angle is in the clockwise direction with respect to -x axis.

We need to find Angle counterclockwise from the +x axis.

So,

θ = 180° - 56.4°

θ = 123.6°

The given vector is in 2nd quadrant

4 0

4 years ago

6. What's a stalactite?

iogann1982 [59]

I think it's d......... Good luck

8 0

3 years ago