<h2>
Answer:</h2>
(a) 10N
<h2>
Explanation:</h2>
The sketch of the two cases has been attached to this response.
<em>Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.</em>
In this case, a frictional force 
is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;
∑F = ma -------------------(i)
Where;
∑F = effective force acting on the object (box)
m = mass of the object
a = acceleration of the object
∑F = F -
m = 50kg
a = 0 [At constant velocity, acceleration is zero]
<em>Substitute these values into equation (i) as follows;</em>
F - = m x a
F - = 50 x 0
F - = 0
F = -------------------(ii)
<em>Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²</em>
In this case, the same frictional force is opposing the movement of the box.
∑F = 1.5F -
m = 50kg
a = 0.1m/s²
<em>Substitute these values into equation (i) as follows;</em>
1.5F - = m x a
1.5F - = 50 x 0.1
1.5F - = 5 ---------------------(iii)
<em>Substitute </em><em> = F from equation (ii) into equation (iii) as follows;</em>
1.5F - F = 5
0.5F = 5
F = 5 / 0.5
F = 10N
Therefore, the value of F is 10N
<em />
The option that could be the hypothesis for this experiment is that D. Abstract paintings may elicit feelings of stress as students try to determine the meanings of the paintings; therefore, abstract paintings may cause college students to report lower feelings of peace.
<h3>What is a hypothesis?</h3>
It should be noted that a hypothesis simply means the proposed explanation made on the basis of limited evidence.
From the information, Smith is conducting an experiment to determine if paintings of landscapes produce more peaceful feelings than abstract paintings.
Therefore, the option that could be the hypothesis for this experiment is that abstract paintings may elicit feelings of stress as students try to determine the meanings of the paintings; therefore, abstract paintings may cause college students to report lower feelings of peace.
Learn more about hypothesis on:
brainly.com/question/11555274
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Answer:
The visible light frequency is 400 THz to 700 THz, approximately. A THz is a Terahertz, which is a unit of frequency equal to one trillion Hertz.
Answer:4.34 miles
Explanation:
first Elevation =
After 1 minute Elevation changes to 
Ditsance travelled in 1 minute =
=10 mile
Now
tan59=
H=xtan59
tan19=
H=
Equating H
we get
1.319x=10tan19
x=2.61 miles
H=
=4.34 miles
Answer:
i)20369 photons
ii) 40 ps
Explanation:
Momentum of one Sodium atom:
In other to stop it, it must absorb the same momentum in photons:
Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:
