1. If the atomic number is 25, how many protons does it have?

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il63 [147K]

Explanation:

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5 0

1 year ago

Read 2 more answers

You are performing a knee extension exercise. You hold a 20kg weight at full knee extension. The weight is 0.4m from your knee j

dmitriy555 [2]

Answer:

The moment is -78.4 N-m (clockwise).

Explanation:

Given:

Mass of the object (m) = 20 kg

Distance of the object from the knee joint (d) = 0.4 m

Weight of leg is not considered.

Acceleration due to gravity (g) = 9.8 m/s²

Now, weight of the object is equal to the product of its mass and acceleration due to gravity. So,

Weight = Mass × Acceleration due to gravity

= $mg=20\times 9.8 =196\ N$

We know that, moment of a force about a point is defined as the product of force applied and the perpendicular distance between the point and the line of application of force.

Moment of the given weight about the knee joint is given as:

Moment about knee joint = Weight × Distance from knee joint to weight

Moment about knee joint = 196 × 0.4 = 78.4 Nm

Now, from the diagram below, we can observe that, the weight acts vertically down and thus the sense of rotation about the knee joint at point O is clockwise. So, moment is negative.

Therefore, the moment is -78.4 N-m (clockwise).

7 0

3 years ago

An infinitely long cylinder of radius R has linear charge density λ. The potential on the surface of the cylinder is V0, and the

tamaranim1 [39]

Answer:

V = V_0 - (lamda)/(2pi(epsilon_0))*ln(R/r)

Explanation:

Attached is the full solution

5 0

2 years ago

Help me please this is for physics

Yuri [45]

<h2>Hello there! :)</h2>

It's a pleasure to be helping you today with your<u> physics question!</u>

Answer:

$23.1m/s$

Explanation:

We want to find the initial speed of the ball.

To do this, we have to apply the formula for the time of flight of a projectile:

$T=\frac{2_{v0~sin 0} }{g}$

where θ = angle of flight

g = acceleration due to gravity

v0 = initial speed

Therefore, substituting the given values into the formula, we have that:

$\boxed{4.2=\frac{2~x~_{v0~sin63} }{9.8}}$

⇒ 2 × $_{v0}$ ×0.8910= 9.8 × 4.2

⇒ $\boxed{{v0}=\frac{9.8~times~4.2}{2~times~0.8910}}$

$\boxed{{v0} =23.1m/s}$

That is the initial speed of the ball.

<em />

<em>I hope this helps you!</em>

<em>Good Luck with your Assignment!</em>

3 0

2 years ago

Find the minimum uncertainty in the speed of a uranium nucleus having mass 4e-25 kg if we know the position of the uranium nucle

Sholpan [36]

Answer:

13180 m/s

Explanation:

Mass is a measure of the amount of matter in an object. Mass is usually measured in grams (g) or kilograms (kg)

The nucleus is a membrane-bound organelle that contains genetic material (DNA) of eukaryotic organisms. As such, it serves to maintain the integrity of the cell by facilitating transcription and replication processes.

Having understood those terms, lets calculate the minimum uncertainty in the speed of a uranium nucleus having mass 4e-25 kg if we know the position of the uranium nucleus to within 1e-14 m, that is, to about its own size.

Please kindly check attachment for the step by step explaination.

5 0

2 years ago