Answer:
The time taken to stop the box equals 1.33 seconds.
Explanation:
Since frictional force always acts opposite to the motion of the box we can find the acceleration that the force produces using newton's second law of motion as shown below:
Given mass of box = 5.0 kg
Frictional force = 30 N
thus
Now to find the time that the box requires to stop can be calculated by first equation of kinematics
The box will stop when it's final velocity becomes zero
Here acceleration is taken as negative since it opposes the motion of the box since frictional force always opposes motion.
Answer:
f1= -350cm or -3.5m
f2= 22.1cm or 0.221m
Explanation:
A person is nearsighted when the person's far point is less than infinity. A diverging lens is normally used to correct this eye defect. A diverging lens has a negative focal length as seen in the solution attached.
Farsightedness is when a person's near point is farther than 25cm. This eye defect is corrected using a converging lens. The focal length of a converging lens is positive. This is evident in the solution attached. The near point is also referred to as the least distance of distinct vision.
Answer:
Given: V = 220V, Pmin = 360W, Pmax = 840W
For minimum heating case:
We know that
Pmin = VI
360 = 220 X I
I = 1.63 amp
R = V/I
R = 220/1.63
R = 134.96ohms
For maximum heating case:
We know that
Pmax = VI
840 = 220 X I
I = 3.81 amp
R = V/I
R = 220/3.81
R = 57.74 ohms
The final velocity of the projectile when it strikes the ground below is 198.51 m/s.
<h3>
Time of motion of the projectile</h3>
The time taken for the projectile to fall to the ground is calculated as follows;
h = vt + ¹/₂gt²
where;
- h is height of the cliff
- v is velocity
- t is time of motion
265 = (185 x sin45)t + (0.5)(9.8)t²
265 = 130.8t + 4.9t²
4.9t² + 130.8t - 265 = 0
solve the quadratic equation using formula method,
t = 1.89 s
<h3>Final velocity of the projectile</h3>
vyf = vyi + gt
where;
- vyf is the final vertical velocity
- vyi is initial vertical velocity
vyf = (185 x sin45) + (9.8 x 1.89)
vyf = 149.322 m/s
vxf = vxi
where;
- vxf is the final horizontal velocity
- vxi is the initial horizontal velocity
vxf = 185 x cos(45)
vxf = 130.8 m/s
vf = √(vyf² + vxf²)
where;
- vf is the speed of the projectile when it strikes the ground below
vf = √(149.322² + 130.8²)
vf = 198.51 m/s
Learn more about final velocity here: brainly.com/question/6504879
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Option (b) is correct. The certain materials can act as superconductors at a very low temperature.
Explanation:
The Superconductivity of a material is the property of the particular substance to provide no resistance to the path of the current through it. The current does not face any hindrance due to the motion of the other particles inside the conductor.
The superconductivity of a substance leads to the flow of current through the substance or the material without any hindrance. The resistance of a substance is due to the motion of the particles inside it. If all the motion occurring inside the substance are seized, there will be no resistance offered by the conductor.
Therefore, the superconductivity can be defined as the state where all the motions inside the a material are seized. This occurs at a very low temperature. The absolute zero temperature
is regarded as the temperature where there is no motion in any particle.
Thus, Option (b) is correct. The certain materials can act as superconductors at a very low temperature.
Learn More:
1. An electrical shock happens when electric brainly.com/question/3059888
2. A capacitor with capacitance (c) = 4.50 μf is connected to a 12.0 v battery brainly.com/question/8892837
3. Reason for the difference in resistance of bulb brainly.com/question/10421964
Answer Details:
Grade: High School
Subject: Physics
Chapter: Conductivity
Keywords:
material, superconductor, motion, pressure, cold, temperature, substance, material, conditions, superconductivity.
