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
Fiesta28 [93]
3 years ago
15

A girl throws a stone from a bridge. Consider the following ways she might throw the stone. The speed of the stone as it leaves

her hand is the same in each case, and air resistance is negligible.Case A: Thrown straight up.Case B: Thrown straight down.Case C: Thrown out at an angle of 45 above horizontal.Case D: Thrown straight out horizontally.In which case will the speed of the stone be greatest when it hits the water below?

Physics
2 answers:
Len [333]3 years ago
3 0

Answer:

the velocity in all the cases will be same.

Explanation:

given,

girl throws a stone from the bridge

air is friction less

we have to find from the given cases in which case the velocity of stone will be greatest.

According to Work energy theorem work done by the sum of all the force is equal to kinetic energy.

As the air is frictionless hence the speed depend upon the height from which the stone is thrown.

height in all the cases is same.

so, the velocity in all the cases will be same.

Fiesta28 [93]3 years ago
3 0

The speed of the stone hitting the water below will be the same for every case.

\texttt{ }

<h3>Further explanation</h3>

Acceleration is rate of change of velocity.

\large {\boxed {a = \frac{v - u}{t} } }

\large {\boxed {d = \frac{v + u}{2}~t } }

<em>a = acceleration ( m/s² )</em>

<em>v = final velocity ( m/s )</em>

<em>u = initial velocity ( m/s )</em>

<em>t = time taken ( s )</em>

<em>d = distance ( m )</em>

Let us now tackle the problem!

\texttt{ }

<u>Given:</u>

height of the stone = h

initial speed of the stone = u

<u>Unknown:</u>

final speed of the stone = v = ?

<u>Solution:</u>

<h3>Case A:</h3>

v^2 = u^2 -2gh

v^2 = u^2 - 2g(-h)

v^2 = u^2 + 2gh

\boxed {v = \sqrt{u^2 + 2gh}}

\texttt{ }

<h3>Case B:</h3>

v^2 = u^2 - 2gh

v^2 = (-u)^2 - 2g(-h)

v^2 = u^2 + 2gh

\boxed {v = \sqrt{u^2 + 2gh}}

\texttt{ }

<h3>Case C:</h3>

v_x = u \cos \theta

\texttt{ }

(v_y)^2 = (u \sin \theta)^2 - 2gh

(v_y)^2 = (u \sin \theta)^2 - 2g(-h)

(v_y)^2 = (u \sin \theta)^2 + 2gh

\texttt{ }

v^2 = (v_x)^2 + (v_y)^2

v^2 = (u \cos \theta)^2 + (u \sin \theta)^2 + 2gh

v^2 = u^2 ( \cos^2 \theta + \sin^2 \theta) + 2gh

v^2 = u^2 (1) + 2gh

\boxed{v = \sqrt{u^2 + 2gh}}

\texttt{ }

<h3>Case D:</h3>

v_x = u \cos \theta

v_x = u \cos 0^o

v_x = u

\texttt{ }

(v_y)^2 = (u \sin \theta)^2 - 2gh

(v_y)^2 = (u \sin 0^o)^2 - 2g(-h)

(v_y)^2 = (0)^2 + 2gh

(v_y)^2 = 2gh

\texttt{ }

v^2 = (v_x)^2 + (v_y)^2

v^2 = (u)^2 + 2gh

\boxed{v = \sqrt{u^2 + 2gh}}

\texttt{ }

From information above , we could conclude that the speed of the stone hitting the water below will be the same for every case.

\texttt{ }

<h3>Learn more</h3>
  • Velocity of Runner : brainly.com/question/3813437
  • Kinetic Energy : brainly.com/question/692781
  • Acceleration : brainly.com/question/2283922
  • The Speed of Car : brainly.com/question/568302

\texttt{ }

<h3>Answer details</h3>

Grade: High School

Subject: Physics

Chapter: Kinematics

\texttt{ }

Keywords: Velocity , Driver , Car , Deceleration , Acceleration , Obstacle , Projectile , Motion , Horizontal , Vertical , Release , Point , Ball , Wall

You might be interested in
Why we don’t feel atmospheric pressure?
Veseljchak [2.6K]

Answer:

The reason we can't feel it is that the air within our bodies (in our lungs and stomachs, for example) is exerting the same pressure outwards, so there's no pressure difference and no need for us to exert any effort.

8 0
2 years ago
Read 2 more answers
A 13-cm-diameter cd has a mass of 25 g . part a what is the cd's moment of inertia for rotation about a perpendicular axis throu
faltersainse [42]
<span>Answer: For a disc, the moment of inertia about the perpendicular axis through the center is given by 0.5MR^2. where M is the mass of the disc and R is the radius of the disc. For the axis through the edge, use parallel axis theorem. I = I(axis through center of mass) + M(distance between the axes)^2 = 0.5MR^2 + MR^2 (since the axis through center of mass is the axis through the center) = 1.5 MR^2</span>
8 0
3 years ago
Read 2 more answers
the moderate temperatures of islands throughout the world has much to do with water's vast supply of internal energy. high evapo
Ad libitum [116K]

High specific heat of the water. Option (c)

What is Specific heat?

The amount of heat required to increase the temperature of one gram of a substance by one degree Celsius is referred to as the substance's specific heat. Typically, calories or joules are used per gram and degree Celsius when referring to the units of specific heat.

The moderate temperature of islands has much to do with the water's high specific heat. The typical off-water is more significant than this clear land or soil. Due to this fact, water absorbs and releases eat more slowly. In comparison to the land.

Hence, the water has high specific heat.

To learn more about specific heat the link is given below:

brainly.com/question/12982780?

#SPJ4

3 0
1 year ago
If a rock is thrown upward on the planet mars with a velocity of 11 m/s, its height (in meters) after t seconds is given by h =
Butoxors [25]
(a) 3.56 m/s 
(b) 11 - 3.72a 
(c) t = 5.9 s 
(d) -11 m/s  
For most of these problems, you're being asked the velocity of the rock as a function of t, while you've been given the position as a function of t. So first calculate the first derivative of the position function using the power rule. 
y = 11t - 1.86t^2 
y' = 11 - 3.72t 
Now that you have the first derivative, it will give you the velocity as a function of t. 
(a) Velocity after 2 seconds. 
y' = 11 - 3.72t 
y' = 11 - 3.72*2 = 11 - 7.44 = 3.56 
So the velocity is 3.56 m/s  
(b) Velocity after a seconds. 
y' = 11 - 3.72t 
y' = 11 - 3.72a  
So the answer is 11 - 3.72a  
(c) Use the quadratic formula to find the zeros for the position function y = 11t-1.86t^2. Roots are t = 0 and t = 5.913978495. The t = 0 is for the moment the rock was thrown, so the answer is t = 5.9 seconds.  
(d) Plug in the value of t calculated for (c) into the velocity function, so: 
y' = 11 - 3.72a
 y' = 11 - 3.72*5.913978495
 y' = 11 - 22
 y' = -11 
 So the velocity is -11 m/s which makes sense since the total energy of the rock will remain constant, so it's coming down at the same speed as it was going up.
3 0
3 years ago
g Two radiation modes (one at the center frequency lIo and the other at lIO+?lI) are excited with 1000 photons each. Determine t
Schach [20]

Answer:

a) P=0.25x10^-7

b) R=B*N2*E

c) N=1.33x10^9 photons

Explanation:

a) the spontaneous emission rate is equal to:

1/tsp=1/3 ms

the stimulated emission rate is equal to:

pst=(N*C*o(v))/V

where

o(v)=((λ^2*A)/(8*π*u^2))g(v)

g(v)=2/(π*deltav)

o(v)=(λ^2)/(4*π*tp*deltav)

Replacing values:

o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2

the probability is equal to:

P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7

b) the rate of decay is equal to:

R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system

c) the number of photons is equal to:

N=(1/tsp)*(V/C*o)

Replacing:

N=100/(3*3x10^10*8.3x10^-19)

N=1.33x10^9 photons

7 0
3 years ago
Other questions:
  • How much energy does it take to melt a 16.87 g ice cube? ΔHfus = 6.02 kJ/mol How much energy does it take to melt a 16.87 g ice
    9·1 answer
  • Vector A→ has a magnitude of 8 units and makes an angle of 45° with the positive x-axis. Vector B→ also has a magnitude of 8 uni
    5·2 answers
  • A small ball is attached to one end of a rigid rod with negligible mass. The ball and the rod revolve in a horizontal circle wit
    5·1 answer
  • Find the speed of a 5.6-kg bowling ball that has a kinetic energy of 25.2 J.
    8·1 answer
  • What happens to the amount of friction if you increase the mass of an object?
    5·2 answers
  • What are possible units for impulse? Check all that apply.
    13·1 answer
  • A heat pump receives heat from a lake that has an average winter time temperature of 6o C and supplies heat into a house having
    10·1 answer
  • Help!! HELP HELP HELP HELP
    11·1 answer
  • Johanna is studying what happens to the energy as a ball rolls down a ramp. What is one form of energy that she is studying? gra
    13·2 answers
  • if a girl is running along a straight road with uniform velocity 1.5 metre per second find the acceleration​
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!