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
Aleks04 [339]
3 years ago
9

A stone that is dropped freely from rest traveled half its total height in the last second. With what velocity will it strike th

e ground?​
Physics
2 answers:
Paha777 [63]3 years ago
8 0

Answer:

33.5 m/s

Explanation:

At time t, the displacement is h/2:

Δy = v₀ t + ½ at²

h/2 = 0 + ½ gt²

h = gt²

At time t+1, the displacement is h.

Δy = v₀ t + ½ at²

h = 0 + ½ g (t + 1)²

h = ½ g (t + 1)²

Set equal and solve for t:

gt² = ½ g (t + 1)²

2t² = (t + 1)²

2t² = t² + 2t + 1

t² − 2t = 1

t² − 2t + 1 = 2

(t − 1)² = 2

t − 1 = ±√2

t = 1 ± √2

Since t > 0, t = 1 + √2.  So t+1 = 2 + √2.

At that time, the speed is:

v = at + v₀

v = g (2 + √2) + 0

v = g (2 + √2)

If g = 9.8 m/s², v = 33.5 m/s.

VashaNatasha [74]3 years ago
6 0
Let the total distance from the ground be “h” , so the distance travelled in last one second will be “ h/2”. So as it is free fall , u(initial velocity) = 0.
You might be interested in
A compass needle acts as a(n)
beks73 [17]

Explanation:

A compass needle acts as a Magnet

6 0
2 years ago
Pretty cool, the atoms that exist in your body are some of the same atoms that have existed since the beginning of the universe.
marusya05 [52]

Answer:

was is carl sagan?

Explanation:

please forgive me if im wrong :(

8 0
2 years ago
Read 2 more answers
In the two-slit experiment, monochromatic light of frequency 5.00 × 1014 Hz passes through a pair of slits separated by 2.20 × 1
asambeis [7]

Explanation:

It is given that,

Frequency of monochromatic light, f=5\times 10^{14}\ Hz

Separation between slits, d=2.2\times 10^{-5}\ m

(a) The condition for maxima is given by :

d\ sin\theta=n\lambda

For third maxima,

\theta=sin^{-1}(\dfrac{n\lambda}{d})

\theta=sin^{-1}(\dfrac{n\lambda}{d})

\theta=sin^{-1}(\dfrac{nc}{fd})  

\theta=sin^{-1}(\dfrac{3\times 3\times 10^8\ m/s}{5\times 10^{14}\ Hz\times 2.2\times 10^{-5}\ m})  

\theta=4.69^{\circ}

(b) For second dark fringe, n = 2

d\ sin\theta=(n+1/2)\lambda

\theta=sin^{-1}(\dfrac{5\lambda}{2d})

\theta=sin^{-1}(\dfrac{5c}{2df})

\theta=sin^{-1}(\dfrac{5\times 3\times 10^8}{2\times 2.2\times 10^{-5}\times 5\times 10^{14}})

\theta=3.90^{\circ}

Hence, this is the required solution.

8 0
3 years ago
A speeding Thunderbird left skid marks on the road that were 76.7 m long when it came to a stop. If the acceleration of the car
FrozenT [24]

Answer: 39.2 m/s

Explanation:

You can use the kinematic equation:

v_f^2=v_i^2+2a*d

We know the final velocity because it says it came to a stop. So now all we gotta do is plug in.

0^2=v_i^2+2(-10)(76.7)\\v_i^2=1,534\\v_i=\sqrt{1534} \\=39.166 m/s

4 0
3 years ago
REMARKS The speed found in part (a) is the same as if the woman fell vertically through a distance of 21.9 m. The result of part
sasho [114]

Answer:

Yes, if the system has friction, the final result is affected by the loss of energy.

Explanation:

The result that you are showing is the conservation of mechanical energy between two points in the upper one, the energy is only potential and the lower one is only kinetic.

In the case of some type of friction, the change in energy between the same points is equal to the work of the friction forces

    W_{fr} = ΔEm

    W_{fr} = Em_{f} -Em₀

As we can see now there is another quantity and for which the final energy is lower and therefore the final speed would be less than what you found in the case without friction.

    Em_{f} =W_{fr} + Em₀

 

Remember that the work of the rubbing force is negative, let's write the work of the rubbing force explicitly, to make it clearer

    ½ m v² = -fr d + mgh

    v = √(-fr d 2/m + 2 gh)

    v = √ (2gh - 2fr d/m)

Now it is clear that there is a decrease in the final body speed.

Consequently, if the system has friction, the final result is affected by the loss of energy.

5 0
2 years ago
Other questions:
  • If the net force acting on an object increases by 50 percent, then the acceleration of the object will
    11·1 answer
  • under what conditions would a scale record a weight for an object which is equal to the magnitude of the gravitational force on
    14·2 answers
  • What is the net force necessary for a 1.6 x 103 kg car to accelerate forward at 2.0<br> m/s?
    15·1 answer
  • A laptop computer draws 5 A of current with a voltage of 19 V. Which is the power used by the computer?
    13·2 answers
  • The distance light travels in a year is called _______.
    12·2 answers
  • Bromium has two naturally occurring isotopes: 79br, with an atomic weight of 78.918 amu, and 81br, with an atomic weight of 80.9
    5·1 answer
  • A forward horizontal force of 50 N is applied to a crate. A second horizontal force of
    15·1 answer
  • In any vector space au=bu implies a=b ? Trou or False​
    12·2 answers
  • how many helium-filled balloons would it take to lift a person? assume the person has a mass of 73 kgkg and that each helium-fil
    7·1 answer
  • ANSWER FOR BRAINLIEST
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!