1. During the Middle Ages, armies often attacked castles using large siege engines such as the counterweight trebuchet at left.


You are watching: Which of the following tests uses calipers to assess body composition?

derekwadsworth.com: Some challenges that I could see would be the walls, possibly a moat, tar, and the towers.

Explanation: The wall is obliviously a main problem, trying to get over it or through it is a difficult challenge. The moat (if it has one) means that there is more than likely only one way to get in or out. If it does have tar it means that the attackers are going to be put in a "sticky situation" And finally the towers, they have people at the top shooting arrows down at you, or throwing things at you.



Calculate the de Broglie wavelength of: a) A person running across the room (assume 180 kg at 1 m/s) b) A 5.0 MeV proton

derekwadsworth.com:

a

*

b

*

Explanation:

From the question we are told that

The mass of the person is

*

The speed of the person is

*

The energy of the proton is

*

Generally the de Broglie wavelength is mathematically represented as

*

Here h is the Planck constant with the value

*

So

*

=>

*

Generally the energy of the proton is mathematically represented as

*

Here

*
is the mass of proton with value
*

=>

*

=>

*

=>

*

So

*

so

*

=>

*



In his explanation of the threshold frequency in the photoelectric field, Einstein reasoned that the absorbed photon must have t

derekwadsworth.com:

4.6×10^-7 m or 0.46nm

Explanation:

From

Wo= hc/λ

Where:

Wo= work function of the metal

h= planks constant

c= speed of light

λ= wavelength

λ= hc/Wo

λ= 6.6×10^-34 × 3×10^8/4.30×10^-19

λ= 4.6×10^-7 m






See more: Chart Of Color That Starts With The Letter D ", Colors That Start With The Letter D

If you were trying to cross a river with the shortest possible time, would you aim your boat slightly upstream, directly across