Answer:
Vf = 29.4 m/s
h = 44.1 m
Explanation:
Data:
- Initial Velocity (Vo) = 0 m/s
- Gravity (g) = 9.8 m/s²
- Time (t) = 3 s
- Final Velocity (Vf) = ?
- Height (h) = ?
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Final Velocity
Use formula:
Replace:
Multiply:
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Height
Use formula:
Replace:
Multiply time squared:
Simplify the s², and multiply in the numerator:
It divides:
What is the velocity when falling to the ground?
The final velocity is <u>29.4 meters per seconds.</u>
How high is the building?
The height of the building is <u>44.1 meters.</u>
Answer:
the final velocity of the car is 59.33 m/s [N]
Explanation:
Given;
acceleration of the car, a = 13 m/s²
initial velocity of the car, u = 120 km/h = 33.33 m/s
duration of the car motion, t = 2 s
The final velocity of the car in the same direction is calculated as follows;
v = u + at
where;
v is the final velocity of the car
v = 33.33 + (13 x 2)
v = 59.33 m/s [N]
Therefore, the final velocity of the car is 59.33 m/s [N]
Answer: B. Concrete
Explanation:
Let N = reacting force pressing the bodies in context together (units in Newtons),
The question stated that the force pressing the two mounted/stacked objects together is equal to the weight of the object on top.
We need to start by finding the weight of the piece of wood.
friction is given by
f = μN
The value of f is 22.5,
and from the chart reference the coefficient of friction between wood and stone, μ is 0.30.
22.5 = 75. 0.30
Putting the values into the equation: 22.5 = 0.30N.
Divide both sides by 0.30 to find the value of N:
N= 22.5/0.3 = 75
Now that the piece of wood will be placed on another surface, its weight of 75 Newton is the force pressing the two bodies together.
To determine the new surface, you should find the new coefficient of friction by using the new value of the force of friction given 46.5:
46.5 = µ(75).
Divide both sides by 75 to isolate μ.
The refer chart also indicates that the coefficient of friction equals 0.62 between wood and concrete, so the new surface corresponding to 0.62 is the concrete, which is (B).
Explanation:
A concave mirror can form real, inverted images of various sizes and virtual, erect and enlarged images whereas a concave lens forms only virtual, errect and diminished images.
