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
scoundrel [369]
3 years ago
7

a stone is dropped from rest at an initial height h above the surface of the earth. Show that the speed with which it strikes th

e ground is v
Physics
1 answer:
Ksju [112]3 years ago
5 0

Answer:

v=\sqrt{2gh}

Explanation:

We could use conversation of energy. Total distance the stone will cover will be

h=\frac{1}{2} g t^{2}

the Final velocity will be

v=gt\\v=g\sqrt{\frac{2h}{g} }\\ v=\sqrt{2gh}

You might be interested in
A spectral line from a star is observed to have a wavelength of 656.5 nm. The rest wavelength of this line is 656.8 nm. (a) What
nignag [31]

Answer:

speed of star is  1.37 × 10^{5} m/s

it is approaching to earth because wavelength of star is decreasing than rest

if emit same wavelength it does not move anywhere

it will remain steady condition with respect earth

Explanation:

given data

wavelength = 656.5 nm

rest wavelength = 656.8 nm

to find out

the speed of the star , is it approaching

solution

we know here equation that is

wavelength shift / wavelength at rest  = velocity of source / speed of light

so put all value and find

velocity of source = 3 × 10^{-9} × 3 × 10^{8} / 656.8 × 10^{-9}

velocity of source star = 1.37 × 10^{5} m/s

and

it is approaching to earth because wavelength of star is decreasing than rest

and

if emit same wavelength it does not move anywhere

it will remain steady condition with respect earth

6 0
3 years ago
A pure substance can be a ..................... (a) element (b) compound (c) either element or compound (d)none of these
stiks02 [169]

Answer:

C

Explanation:

An element is a pure substance that can not be broken down into anything simpler

A compound in also a pure substance held together in fixed proportion through chemical bonds

7 0
3 years ago
Read 2 more answers
In which situation is work not being done?
almond37 [142]

AS

work done =W = F.d = F d cosФ     (Ф is angle between force F and displacement d) If a body/object is moving on a smooth surface (friction-less surface ) .There is no force acting on that body.  F=0 so W=FdcosФ= (0)dcosФ ⇒ W=0

Now if a body is facing some amount of force but under the action of force there is no displacement covered. d=0 so W =FdcosФ= F(0)cosФ ⇒W=0

example:  A person is applying a force on rigid wall but wall remains at rest there is no displacement occurs in wall.

The third term upon which work done  dependent is angle between force and displacement i.e Ф. If Ф=90° then W= FdcosФ= Fdcos90⇒ W=0   ( as cos 90°=0)

5 0
3 years ago
When you turn brownie mix into brownies is that a physical change?
kotegsom [21]
No because for example you get a brownie mix and you want to make them well you put all of the mixture in the blender and you finish making them. Well now the brownies are done. well are they still the brownie mix?
5 0
3 years ago
A 1200 kg car reaches the top of a 100 m high hill at A with a speed vA. What is the value of vA that will allow the car to coas
Pavel [41]

Complete question is:

A 1200 kg car reaches the top of a 100 m high hill at A with a speed vA. What is the value of vA that will allow the car to coast in neutral so as to just reach the top of the 150 m high hill at B with vB = 0 m/s. Neglect friction.

Answer:

(V_A) = 31.32 m/s

Explanation:

We are given;

car's mass, m = 1200 kg

h_A = 100 m

h_B = 150 m

v_B = 0 m/s

From law of conservation of energy,

the distance from point A to B is;

h = 150m - 100 m = 50 m

From Newton's equations of motion;

v² = u² + 2gh

Thus;

(V_B)² = (V_A)² + (-2gh)

(negative next to g because it's going against gravity)

Thus;

(V_B)² = (V_A)² - (2gh)

Plugging in the relevant values;

0² = (V_A)² - 2(9.81 × 50)

(V_A) = √981

(V_A) = 31.32 m/s

3 0
3 years ago
Other questions:
  • What kind of image does the lens in a camera produce?
    14·1 answer
  • Convert the following: 9.87 x 108s = _____ h
    12·2 answers
  • Suppose an astrophotographer hands you a picture with star trails taken looking toward the north celestial pole. If the star tra
    11·1 answer
  • Water runs into a fountain, filling all the pipes, at a steady rate of 0.750 m3>s. (a) How fast will it shoot out of a hole 4
    10·1 answer
  • The normal movement of water across this membrane is from high to low ____________ concentration.
    7·1 answer
  • A person is pulled to the right on a sled (total mass of 52.9 kg) across the surface of a frozen pond with a force of 67.7 Newto
    9·1 answer
  • Gymnastics has great benefits for you both your body and mind? True False
    9·2 answers
  • A sound wave traveling in water at 144m/s has a wavelength of 0.5m determine the frequency of the wave
    6·2 answers
  • How to tell cold fronts from warm fronts
    8·1 answer
  • Please help ASAP- A book has a mass of 5 kg, a baby has a mass of 5 kg. Which one weighs more?
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!