Which statement is true about historical models of the solar system?

A ball is thrown with an initial velocity of u=(10i +15j) m/s. Whan it reaches the top of it trajectory neglecting air resistanc

liraira [26]

Answer:

v = (10 i ^ + 0j ^) m / s, a = (0i ^ - 9.8 j ^) m / s²

Explanation:

This is a missile throwing exercise.

On the x axis there is no acceleration so the velocity on the x axis is constant

v₀ₓ = 10 m / s

On the y-axis velocity is affected by the acceleration of gravity, let's use the equation

v_y = $v_{oy}$ - g t

$v_{y}^2 = v_{oy}^2 - 2 g (y - y_o)$

at the highest point of the trajectory the vertical speed must be zero

v_y = 0

therefore the velocity of the body is

v = (10 i ^ + 0j ^) m / s

the acceleration is

a = (0 i ^ - g j⁾

a = (0i ^ - 9.8 j ^) m / s²

5 0

2 years ago

A student wants to draw a model of an atom. Which statement describes how to find the number of neutrons to include in the model

Lesechka [4]

Answer:

Subtract the atomic number from the mass number

Explanation:

The number of neurons in an atom is equal to the difference between the atomic number and the mass number

5 0

1 year ago

An astronaut throws a wrench in interstellar space. How much force is required to keep the wrench moving continuously with const

andreev551 [17]

Answer:

0 N

Explanation:

This is a trick question, the mass of the wrench would be 0 due to it being in space and has no gravitational pull to weight it down. And since acceleration is defined as the rate and change of velocity with no respect of time and the wrench is moving at a constant velocity, that means the velocity is 0. and since F = m*a it would be F = 0 * 0 = 0 N

5 0

2 years ago

Baseball player a bunts the ball by hitting it in such a way that it acquires an initial velocity of 2.4 m/s parallel to the gro

LUCKY_DIMON [66]

Let $\mathbf r_A$ denote the position vector of the ball hit by player A. Then this vector has components

$\begin{cases}r_{Ax}=\left(2.4\,\frac{\mathrm m}{\mathrm s}\right)t\\r_{Ay}=1.2\,\mathrm m-\frac12gt^2\end{cases}$

where $g=9.8\,\dfrac{\mathrm m}{\mathrm s^2}$ is the magnitude of the acceleration due to gravity. Use the vertical component $r_{Ay}$ to find the time at which ball A reaches the ground:

$1.2\,\mathrm m-\dfrac12\left(9.8\,\dfrac{\mathrm m}{\mathrm s^2}\right)t^2=0\implies t=0.49\,\mathrm s$

The horizontal position of the ball after 0.49 seconds is

$\left(2.4\,\dfrac{\mathrm m}{\mathrm s}\right)(0.49\,\mathrm s)=12\,\mathrm m$

So player B wants to apply a velocity such that the ball travels a distance of about 12 meters from where it is hit. The position vector $\mathbf r_B$ of the ball hit by player B has

$\begin{cases}r_{Bx}=v_0t\\r_{By}=1.6\,\mathrm m-\frac12gt^2\end{cases}$

Again, we solve for the time it takes the ball to reach the ground:

$1.6\,\mathrm m-\dfrac12\left(9.8\,\dfrac{\mathrm m}{\mathrm s^2}\right)t^2=0\implies t=0.57\,\mathrm s$

After this time, we expect a horizontal displacement of 12 meters, so that $v_0$ satisfies

$v_0(0.57\,\mathrm s)=12\,\mathrm m$

$\implies v_0=21\,\dfrac{\mathrm m}{\mathrm s}$

5 0

3 years ago

Why did Copernicus want to develop a completely new system for predicting planetary positions? Provide two reasons.

LiRa [457]

Answer:

1) improve the quality of data

2) new system is more simple and elegant

Explanation:

the reason for being selected new system of determining planetary positions are

1) he want to improve the quality of data for having new planetary positioned value.

b) he believed that new system is more simple and elegant for determining planetary positions by both skilled and unskilled user i.e. astronomers and general public

7 0

3 years ago