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goblinko [34]
3 years ago
12

A man standing on top of a 30 m tall building throws a brick downwards with a velocity of 12 m/s. Determine the speed of the bri

ck just before it hits the ground.
Physics
1 answer:
loris [4]3 years ago
3 0

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

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The diagram below shows a subduction zone where oceanic crust is sinking into the mantle underneath continental crust as two
Scrat [10]

Metal ores

Explanation:

in an area where subduction has occurred in times past, metal ores are likely to be found.

Metallic ores find subduction zone regions very favorable to crystallize out of a magma.

  • Ores have different modes of formation.
  • Typically, they are found in hydrothermal vents and black smokers of igneous intrusives.
  • These are igneous terrains where metallic sulfides and other minerals crystallize out of magmatic body.
  • Metals in magma usually have large sizes and do not partition easily in the melt.

At a subduction zone, partial melting of the subducting plate forces magma into nearby country rock as an intrusive and to the ocean floor where they form black smokers.

Learn more:

Rocks brainly.com/question/2740663

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4 0
3 years ago
Two men, Joel and Jerry, each pushes an object that are identical on a horizontal frictionless floor starting from rest. Joel an
Nataliya [291]

Answer:

The work done by Joel is greater than the work done by Jerry.

Explanation:

Let suppose that forces are parallel or antiparallel to the direction of motion. Given that Joel and Jerry exert constant forces on the object, the definition of work can be simplified as:

W = F\cdot \Delta s

Where:

W - Work, measured in joules.

F - Force exerted on the object, measured in newtons.

\Delta s - Travelled distance by the object, measured in meters.

During the first 10 minutes, the net work exerted on the object is zero. That is:

W_{net} = W_{Joel} - W_{Jerry}

W_{net} = F\cdot \Delta s - F\cdot \Delta s

W_{net} = (F-F)\cdot \Delta s

W_{net} = 0\cdot \Delta s

W_{net} = 0\,J

In exchange, the net work in the next 5 minutes is the work done by Joel on the object:

W_{net} = W_{Joel}

W_{net} = F\cdot \Delta s

Hence, the work done by Joel is greater than the work done by Jerry.

7 0
3 years ago
What is time and speed and acceleration
Andre45 [30]

Answer:

Acceleration is the rate of change of velocity with time.Acceleration occurs anytime an object's speed increases or decreases, or it changes direction. Much like velocity, there are two kinds of acceleration: average and instantaneous. Average acceleration is determined over a "long" time interval.

Explanation:

good luck

7 0
3 years ago
What’s the answer?hhhu
allsm [11]

Which one if you want independent variable meaning that means  variable (often denoted by x ) whose variation does not depend on that of another.

7 0
2 years ago
A slingshot is used to launch a stone horizontally from the top of a 20.0 meter cliff. The stone lands 36.0 meters away.
alisha [4.7K]
A) 

     It is a launch oblique, therefore the initial velocity in the vertical direction is zero. Space Hourly Equation in vertical, we have:

S=S_{o}+v_{o}t+ \frac{at^2}{2} \\ 20= \frac{10t^2}{2} \\ t=2s
 
     Through Definition of Velocity, comes:

\Delta v=  \frac{\Delta S}{\Delta t}  \\ v_x= \frac{36}{2}  \\ \boxed {v_{x}=18m/s}


B)
 
     Using the Velocity Hourly Equation in vertical direction, we have:

v_{y}=v_{y_{o}}+gt \\ v_{y}=10\times2 \\ \boxed {v_{y}=20m/s}
  
     The angle of impact is given by:

cos(\theta) =\frac{v_{x}}{v_{y}}  \\ cos(\theta) = \frac{18}{20}  \\ cos(\theta) =0.9 \\ arccos(0.9)=\theta \\ \boxed {\theta \approx 25.84}


If you notice any mistake in my english, please let me know, because i am not native.

7 0
3 years ago
Read 2 more answers
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