Answer:
27.1m/s
Explanation:
Given parameters:
Height of the building = 30m
Initial velocity = 12m/s
Unknown:
Final velocity = ?
Solution:
We apply one of the kinematics equation to solve this problem:
v² = u² + 2gh
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
h is the height
v² = 12² + (2 x 9.8 x 30)
v = 27.1m/s
Answer:
Option D is the correct answer.
Explanation:
The specific gravity of copper is 8.91.
We have
We also have
1 kg = 2.205 lb
1 m = 3.28 ft
Substituting
Option D is the correct answer.
Answer:
<em>216 J</em>
Explanation:
h = 1.8
a = 9.8
m = 12.2
<em>GPE</em> = <em>HAM</em> = 216
Answer:
Gases - Water vapor, Nitrogen, Oxygen etc. Describe what happens to air pressure as you rise upwards in the atmosphere. What causes this change in air pressure? As altitude increases, air pressure will decrease As altitude increases the gas molecules that make up the air spread further apart
When the object is at rest, there is a zero net force due the cancellation of the object's weight <em>w</em> with the normal force <em>n</em> of the table pushing up on the object, so that by Newton's second law,
∑ <em>F</em> = <em>n</em> - <em>w</em> = 0 → <em>n</em> = <em>w</em> = <em>mg</em> = 112.5 N ≈ 113 N
where <em>m</em> = 12.5 kg and <em>g</em> = 9.80 m/s².
The minimum force <em>F</em> needed to overcome <u>maximum</u> static friction <em>f</em> and get the object moving is
<em>F</em> > <em>f</em> = 0.50 <em>n</em> = 61.25 N ≈ 61.3 N
which means a push of <em>F</em> = 15 N is not enough the get object moving and so it stays at rest in equilibrium. While the push is being done, the net force on the object is still zero, but now the horizontal push and static friction cancel each other.
So:
(a) Your free body diagram should show the object with 4 forces acting on it as described above. You have to draw it to scale, so whatever length you use for the normal force and weight vectors, the length of the push and static friction vectors should be about 61.3/112.5 ≈ 0.545 ≈ 54.5% as long.
(b) Friction has a magnitude of 15 N because it balances the pushing force.
(c) The object is in equilibrium and not moving, so the acceleration is zero.
