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3 years ago

Which statement about moons is incorrect?

Physics

2 answers:

mestny [16]3 years ago

5 0

Moons never have an atmosphere.

Liono4ka [1.6K]3 years ago

5 0

The obvious question is B

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Imagine that the ball on the left is given a nonzero initial velocity in the horizontal direction, while the ball on the right c

masya89 [10]

Answer:

vₓ = xg/2y

Explanation:

In this question, let us find the time it takes for the ball on the right that has zero initial velocity to reach the ground.

By newton equation of motion we know that

y = v₀ t - ½ g t²

t = 2y / g

This is the time it takes for the ball on the right to reach the ground; at this time the ball on the left travels a distance

vₓ = x/t

vₓ = xg/2y

Where we assume that x and y are known.

7 0

3 years ago

Rutherford discovered the nucleus of the atom by firing a particles at gold foil. An a particle has a charge of q = +2e and a ma

Readme [11.4K]

Answer: $r_0=3.037\times 10^{-14}m$

Explanation:

Given

charge on alpha particle=+2e

mass of alpha particle= $6.64\times 10^{-27}$ kg

Charge on gold nucleus=+79e

Velocity at r=1m is $1.9\times 10^{7}$

Using Energy conservation

Kinetic energy of particle will be converting to Potential energy as it approaches to nucleus

therefore

$\frac{1}{2}mv^2+U_{r=1m}=U_{closest\ to\ nucleus}$

$\frac{1}{2}\left ( 6.64\times 10^{-27}\right )\left ( 1.9\times 10^{7}^2\right )+\frac{K\left ( 2e\right )\left ( 79e\right )}{1}=\frac{K\left ( 2e\right )\left ( 79e\right )}{r_0}$

$\frac{1}{2}\left ( 6.64\times 10^{-27}\right )\left ( 1.9\times 10^{7}^2\right )=\frac{9\times 10^9\times 158\times \left ( 1.6\times 10^{-19}\right )}{y}\left [\frac{1}{r_0}-\frac{1}{1}\right ]$

on solving we get

$\frac{1}{r_0}=3.292\times 10^{13}$

$r_0=3.037\times 10^{-14}m$

8 0

3 years ago

The distance that a free falling object falls is directly proportional to the square of the time it falls (before it hits the gr

Harman [31]

If the distance is proportional to the square of the time, then the distance in 9 seconds will be (9/8)² as long as the distance in 8 seconds.

(9/8)² = 1.265625

(64 ft) · (1.265625) = <em>81 ft. </em>

4 0

4 years ago

What do all elements in a column in the periodic table have in common?

JulsSmile [24]

Answer:

1, their atoms have the same number of valence electron. because valence electron determine the group of elements.

6 0

3 years ago

A rock is tossed straight up from ground level with a speed of 22 m/s. When it returns, it falls into a hole 9.0 m deep. a. What

Vera_Pavlovna [14]

Answer:

(a) $v_{f}=26.08m/s$

(b) $t=4.906seconds$

Explanation:

We will take ground level as origin and upward is positive direction

the givens are

$y_{i}=0\\y_{f}=-9.0m\\ v_{i}=22m/s$

Part (a)

To find the final velocity we use the kinematic equation

$(v_{f})^{2} =(v_{i})^{2} +2a(y_{f}-y_{i})\\(v_{f})^{2}=(22m/s)^{2}+2(-9.8m/s^{2} ) (-10-0)\\v_{f}=\sqrt{(22m/s)^{2}+2(-9.8m/s^{2} ) (-10-0)} \\v_{f}=26.08m/s$

Part (b)

To find time of rock trip until it touches the ground we will use simple kinematic equation or simple motion equation

$v_{f}=v_{i}+at\\t=\frac{v_{f}-v_{i}}{a}\\ t=\frac{(-26.08m/s)-(22m/s)}{-9.8m/s^{2} }\\t=4.906seconds$

Notice that we substituted vf with negative sign because its direction is downwards

5 0

3 years ago