answer.
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
nirvana33 [79]
2 years ago
12

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in: A)3s B)4s C)6s D)18s E

)36s
Physics
1 answer:
Bad White [126]2 years ago
5 0

Answer:

c) 6s

Explanation: take downwards as positive.

let vf = the velocity of the stone when it hits the ground, vi = 0  be the starting velocity of the stone. r0 = 175m be the height of the building.

(vf)^2 = (vi)^2 + 2g(r-r0)

(vf)^2 = 2g(r0)

     vf =  \sqrt{2g(r0)}  

         = \sqrt{2×9.8×(175)}  

         = 58.6 m/s

then:

vf = vi + g×t

vf = g×t

 t = vf/g

   = (58.6)/(9.8)

   = 6s

Therefore, it will take the stone 6 seconds to reach the gound.

You might be interested in
A circular pipe of 25-mm outside diameter is placed in an airstream at 25C and 1-atm pressure. The air moves in cross flow over
kifflom [539]

Answer:

f_D = =3.24 N/m

Explanation:

data given

properties of air\nu\ of air =19.31*10^{-6} m2/s

\rho = 1.048 kg/m3

k = 0.0288 W/m.K

WE KNOW THAT

Reynold's number is given as

Re =\frac{VD}{\nu}

      = \frac{ 15*0.025}{19.31*10^{-6}}

      = 1.941 *10^4

drag coffecient is given as

C_D = \frac{f_D}{A_f\frac{\rho v^2}{2}}

solving for f_D

f_D = C_D A_f*\frac{\rho v^2}{2}

     =C_D D*\frac{\rho v^2}{2}

Drag coffecient for smooth circular cylinder is 1.1

therefore Drag force is

f_D = 1.1*0.025 *\frac{1.048*15^2}{2}

f_D = =3.24 N/m

4 0
2 years ago
Marcus can drive his boat 24 miles down the river in 2 hours but takes 3 hours to return upstream. Find the rate of the boat in
notsponge [240]

Answer:

speed of boat as

v_b = 10 mph

river speed is given as

v_r = 2 mph

Explanation:

When boat is moving down stream then in that case net resultant speed of the boat is given as

since the boat and river is in same direction so we will have

v_1 = v_r + v_b

Now when boat moves upstream then in that case the net speed of the boat is opposite to the speed of the river

so here we have

v_2 = v_b - v_r

as we know when boat is in downstream then in that case it covers 24 miles in 2 hours

v_1 = \frac{24}{2} = 12 mph

also when it moves in upstream then it covers same distance in 3 hours of time

v_2 = \frac{24}{3} = 8 mph

v_b + v_r = 12 mph

v_b - v_r = 8 mph

so we have speed of boat as

v_b = 10 mph

river speed is given as

v_r = 2 mph

8 0
2 years ago
Read 2 more answers
abin is doing work by lifting a bowling ball. Which statement could be made about the energy in this situation?
PtichkaEL [24]
The statement that could be made about the energy in this situation would be :
It being transferred from his arms muscles to the ball.

The muscle contraction from his arms created a force that could be used to lift the ball up.<span />
8 0
2 years ago
Read 2 more answers
A third point charge q3 is now positioned halfway between q1 and q2. The net force on q2 now has a magnitude of F2,net = 14.413
natima [27]

Answer:

The value of  charge q₃ is 40.46 μC.

Explanation:

Given that.

Magnitude of net force F=14.413\ N

Suppose a point charge q₁ = -3 μC is located at the origin of a co-ordinate system. Another point charge q₂ = 7.7 μC is located along the x-axis at a distance x₂ = 8.2 cm from q₁. Charge q₂ is displaced a distance y₂ = 3.1 cm in the positive y-direction.

We need to calculate the distance

Using Pythagorean theorem

r=\sqrt{x_{2}^2+y_{2}^2}

Put the value into the formula

r=\sqrt{(8.2\times10^{-2})^2+(3.1\times10^{-2})^2}

r=0.0876\ m

We need to calculate the magnitude of the charge q₃

Using formula of net force

F_{12}=kq_{2}(\dfrac{q_{3}}{r_{3}^2}+\dfrac{q_{1}}{r_{1}^2})

Put the value into the formula

14.413=9\times10^{9}\times7.7\times10^{-6}(\dfrac{q_{3}}{(0.0438)^2}+\dfrac{-3\times10^{-6}}{(0.0876)^2})

(\dfrac{q_{3}}{(4.38\times10^{-2})^2}+\dfrac{-3\times10^{-6}}{(0.0876)^2})=\dfrac{14.413}{9\times10^{9}\times7.7\times10^{-6}}

\dfrac{q_{3}}{(0.0438)^2}=207\times10^{-4}+3.909\times10^{-4}

q_{3}=0.0210909\times(0.0438)^2

q_{3}=40.46\times10^{-6}\ C

q_{3}=40.46\ \mu C

Hence, The value of  charge q₃ is 40.46 μC.

5 0
2 years ago
Which type of wave can transmit energy through a vacuum?
m_a_m_a [10]
The wave that can transmit energy through a vacuum is a electromagnetic wave
4 0
2 years ago
Read 2 more answers
Other questions:
  • A parachute works because the canvas of the parachute is acted upon by __________.
    5·2 answers
  • A 3.0-kilogram mass is traveling in a circle of 0.20-meter radius with a speed of 2.0 meters per second. what is the centripetal
    7·1 answer
  • The free-body diagram of a crate is shown. What is the net force acting on the crate? 352 N to the left 176 N to the left 528 N
    11·2 answers
  • Calculate the true mass (in vacuum) of a piece of aluminum whose apparent mass is 4.5000 kg when weighed in air. The density of
    15·1 answer
  • Some of the fastest dragsters (called "top fuel) do not race for more than 300-400m for safety reasons. Consider such a dragster
    5·1 answer
  • The pH of pure water at 25°C is 7.0. The enthalpy change of the autoionization of water is +55.89 kJ/mol. What is the pH of pure
    9·1 answer
  • A student sits motionless on a stool that can turn friction-free about its vertical axis (total rotational inertia I). The stude
    8·1 answer
  • luggage handler pulls a 20.0 kg suitcase up a ramp inclined at 34.0 ∘ above the horizontal by a force F⃗ of magnitude 165 N that
    6·1 answer
  • Consider the following:
    10·1 answer
  • What is Otter's average velocity over his entire trip when it takes him 2 minutes to walk 100 meters north and another 1 minute
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!