T o a stationary observer, a man jogs east at 2.5 m/s and a woman jogs west at 1.5 m/s. from the woman's frame of reference, what is the man's velocity? it is 4m/s east
Answer:
The answer is "between 20 s and 30 s".
Explanation:
Calculating the value of positive displacement:


Calculating the value of negative displacement upon the time t:




That's why its value lie in "between 20 s and 30 s".
The question is incomplete. Here is the entire question.
A jetboat is drifting with a speed of 5.0m/s when the driver turns on the motor. The motor runs for 6.0s causing a constant leftward acceleration of magnitude 4.0m/s². What is the displacement of the boat over the 6.0 seconds time interval?
Answer: Δx = - 42m
Explanation: The jetboat is moving with an acceleration during the time interval, so it is a <u>linear</u> <u>motion</u> <u>with</u> <u>constant</u> <u>acceleration</u>.
For this "type" of motion, displacement (Δx) can be determined by:

is the initial velocity
a is acceleration and can be positive or negative, according to the referential.
For Referential, let's assume rightward is positive.
Calculating displacement:


= - 42
Displacement of the boat for t=6.0s interval is
= - 42m, i.e., 42 m to the left.
Answer:
The atomic weight in g/mole of the metal (molar mass) is 8.87.
Explanation:
To begin, it is possible to assume that, as a sample, it has 100 g of the compound. This means that:
- 52.92% metal: 52.92 g M
- 47.80% oxygen: 47.80 g O
Using the molar mass of oxygen, which is 16 g / mol, it is possible to calculate the amount of moles of oxygen present in the sample using the rule of three:

moles of oxygen=2.9875
The chemical formula of metal oxide tells you that:
2 M⁺³ + 3 O²⁻ ⇒ M₂O₃
In the previous equation you can see that you need 3 oxygen anions to react with two metal cations. Then:

You have 52.92 g of metal in the sample, then the molar mass of the metal is:

molar mass≅ 8.87 g/mol
<u><em> The atomic weight in g/mole of the metal (molar mass) is 8.87.</em></u>
The closest match to this value is Beryllium (Be), which has an atomic mass of 9.0122 g / mol.
Answer:
binding energy is 99771 J/mol
Exlanation:
given data
threshold frequency = 2.50 ×
Hz
solution
we get here binding energy using threshold frequency of the metal that is express as
..................1
here E is the energy of electron per atom
and h is plank constant i.e.
and x is binding energy
and here N is the Avogadro constant =
so E will
E =
so put value in equation 1 we get
= 2.50 ×
×
solve it we get
x = 99770.99
so binding energy is 99771 J/mol