1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alexandra [31]
3 years ago
7

A person standing at the edge of a seaside cliff kicks a stone, horizontally over the edge with a velocity of 18 m/s. The cliff

is 52 m above the waters surface
A. How long does it take for the stone to fall to the water
B. What is the vertical velocity component of the stone just before it hits the water
C. What is the horizontal velocity component of the stone just before it hits the water
D. What is the total velocity of the stone just before it hits the water ?
Physics
1 answer:
madreJ [45]3 years ago
6 0

<u>Answer:</u>

A) The time taken by the stone to reach the ground will be 3.257 Seconds

B) The Initial vertical velocity will be zero

 C) The horizontal velocity doesn’t change, so it remains the same i.e., 18m/s.

D) The total velocity of the stone just before it hits the water is 36.645 m/s.

A)<u>Explanation :</u>

When the stone is kicked, there are two components act on the stone. One is in the horizontal direction, and the other in downward vertical direction.

Also Initial vertical component of velocity will be zero as the stone is kicked horizontally.

So, the time taken will be given by applying Newton’s Equation of Motion

Or, y=v_{i} t+\frac{1}{2} g t^{2}

Where y = vertical downward distance

v_i=initial vertical velocity=0 m/s

t = time taken to reach the ground

Substituting the values in the above equation, we find

-52 = 0 + \frac{-9.8 \times t^{2}}{2}

or, t^2= \frac{-52 \times 2}{-9.8}

or, t =\sqrt{\frac{1040}{98}}  = 3.257 s

B) Explanation

The Initial vertical velocity will be zero as the stone is kicked horizontally

C)Explanation

The horizontal velocity component is not under the influence of gravity, so it remains the same, and moves constant velocity horizontally.

D)  Explanation

We will firstly find the final vertical velocity using one of the equations of motion

v_f= \mathrm{v}_{\mathrm{i}}+\mathrm{at}^{2}

Substituting the values in the above equation, we find

v_f =0-9.8 \times 3.257=-31.92 m/s

Now, Total Velocity (v) is given by

v = \sqrt{v_{x}^{2}+v_{y}^{2}}

where,

v_x= Horizontal velocity

v_y= Vertical velocity

Substituting the values in the above equation, we find

v = \sqrt{18^{2}+31.92^{2}}= 36.645 m/s

You might be interested in
what is the mechanical advantage of a crowbar when a worker uses 10N of force to pry open a window that has a resistance of 500N
Oksana_A [137]

Answer:

50

Explanation:

The mechanical advantage of a machine is given by

MA=\frac{F_{out}}{F_{in}}

where

F_{out} is the output force

F_{in} is the input force

For the crowbar in this problem,

F_{in}=10 N is the force in input applied by the worker

F_{out}=500 N is the force that the machine must apply in output to overcome the resistance of the window and to open it

Substituting into the equation, we find

MA=\frac{500}{10}=50

3 0
3 years ago
Read 2 more answers
A 1 m long wire of diameter 1mm is submerged in an oil bath of temperature 25-degC. The wire has an electrical resistance per un
Zarrin [17]

Answer:

steady state temperature =88.7deg C

t=time within  1 deg C of it steady state is 8.31s

Explanation:

A 1 m long wire of diameter 1mm is submerged in an oil bath of temperature 25-degC. The wire has an electrical resistance per unit length of 0.01 Ω/m. If a current of 100 A flows through the wire and the convection coefficient is 500W/m2K, what is the steady state temperature of the wire? From the time the current is applied, how long does it take for the wire to reach a temperature within 1-degC of the steady state value? The density of the wire is 8,000kg/m3, its heat capacity is 500 J/kgK and its thermal condu

The diameter of the wire is known to be=1mm

properties=

The density of the wire is 8,000 kg/m3,

heat capacity is 500 J/kgK

themal conductivity is 20W/m.K

electrical resistance per unit length of 0.01 Ω/m

from lump capavity method

B_{i} =\frac{hr/2}{k}

500*(2.5*10^-4)/20

0.006<0.1

we know also, to find steady state temperature

\piDh(T-Tinf)=I^{2} R_{e}

make T the subject of the equation , we have

T=25+\frac{100^2*0.01}{\pi*0.001*500 }

T=88.7 degC

rate of chnage in temperature

dT/dt=\frac{I^2*Re}{rho*c*\pi*D^2/4 } -\frac{4h}{rho*c*D} (T-Tinf)

at t=o and integrating both sides\frac{T-Tinf-(I^2*Re/\pi*Dh) }{Ti-Tinf-(I^2*Re/\pi*Dh } =exp\frac{-4ht}{rho*c*D}

we have

\frac{87.7-25-63.7}{25-25-63.7} =exp\frac{4*500t}{8000*500*0.001}

t=8.31s

steady state temperature =88.7deg C

t=time within  1 degC of it steady stae is 8.31s

7 0
3 years ago
an experiment is set up to measure the effect of a gasoline additive on fuel consumption rate. what would be the control in this
Tamiku [17]
The control setup in this experiment would be one tank that does not contain any of the additives. Since the tanks with the gasoline additives would need to be compared with a tank that is not affected by the results of these additives.
4 0
3 years ago
A vinyl record is played by rotating the record so that an approximately circular groove in the vinyl slides under a stylus. Bum
AleksandrR [38]

Answer:

Hits per second=199 hit/s

Explanation:

#Given the angular velocity, \omega=33\frac{1}{3} rev/min , radius of the record r=0.1m and the distance between any two successive bumps on the groove as d=1.75mm.

The linear speed of the record in meters per second is:

v=\omega r=33\frac{1}{3}\times\frac{2\pi}{60}\times 10\times 10^{_2}\\\\=0.3843m/s\\

#From v above, if the bumps are uniformly separated by 1m, then the rate at which they hit the stylus is:

Hits/second=v/d    \ \ \ \ d=1.75mm\\\\=0.3483/0.000175\\\\=199.0385714\approx 199

Hence the bumps hit the stylus at around 199hit/s

8 0
3 years ago
A block of mass, m, sits on the ground. A student pulls up on
kakasveta [241]

Answer a

Explanation: a

3 0
3 years ago
Other questions:
  • Steam undergoes an adiabatic expansion in a piston–cylinder assembly from 100 bar, 360°C to 1 bar, 160°C. What is work in kJ per
    5·1 answer
  • Us
    7·1 answer
  • Kirchhoff's loop rule for circuit analysis is an expression of which of the following? Conservation of charge Conservation of en
    6·1 answer
  • Why does a siren have a lower pitch as it moves away from you? A The period of the sound wave is decreased B The amplitude of th
    15·2 answers
  • HELP PLEASE!!! I'M REALLY BAD AT MECHANICAL ENERGY!!!
    6·1 answer
  • What are the density, specific gravity and mass of the air in a room whose dimensions are 4 m * 6 m * 8 m at 100 kPa and 25 C.
    6·1 answer
  • Scientists in a test lab are testing the hardness of a surface before constructing a building. Calculations indicate that the en
    10·1 answer
  • Do not have definite size and always take the shape of their container,
    5·2 answers
  • Identifying the factors contributing to and acting as determinant factors of health disparities during the program theory and de
    12·1 answer
  • A lorry of mass 12,000kg travelling at a velocity of 2 m/s collides with a stationary car of mass 1500kg. The vehicles move toge
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!