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
levacccp [35]
3 years ago
8

I NEED HELP I AM SO CONFUSED, WILL GIVE BRAIN.

Physics
1 answer:
MakcuM [25]3 years ago
5 0

Answer:

210

Explanation:

A ball rolls horizontally off the cliff at a speed of 30 m/s. It takes 7 seconds for the ball to hit the ground. What is the height of the cliff and the horizontal distance traveled by the ball?

S = (1/2)*9.8 m/s^2 * 7^2 = 240.1 m if the ball is very dense so air resistance, and therefore terminal velocity, can be ignored.

S = v * t = 30 m/s * 7 s = 210 m for the horizontal distance, again assuming negligible air resistance.

You might be interested in
The farther a star is away from earth, the more it is
Darya [45]
The more it is Red shifted.
8 0
4 years ago
Read 2 more answers
Can u answer 4 and 5 for me
Luda [366]
I don’t know what the answers are
8 0
4 years ago
A machine is supplied energy at a rate of 4,000 W and does useful work at a rate of 3,760 W. What is the efficiency of the machi
Dmitry_Shevchenko [17]
                = (3,760 joule/sec) / (4,000 joule/sec)
 
               =    3,760 / 4,000  =  0.94  =  94%
8 0
4 years ago
A student is doing a lab experiment in which she uses diffraction to measure the width of a shaft of her hair. She shines a 530
professor190 [17]

Answer:

.09 mm

Explanation:

In case of diffraction by single slit with width a the width of central maxima is given below

width = 2 λD/a

where λ is wavelength of light , D is distance of screen , a is width o slit

substituting the given values

14 x 10⁻³ = \frac{2\times530\times10^{-9}\times1.2}{a}

a = .09 mm

b) If a is greater , width of central maxima will be less wide.

7 0
4 years ago
The Chernobyl reactor accident in what is now Ukraine was the worst nuclear disaster of all time. Fission products from the reac
Anna35 [415]

Answer:

The correct answer is "53.15 days".

Explanation:

Given that:

Half life of 131_{I},

T_{\frac{1}{2} }= 8 \ days

  • Let the initial activity be "R_o".
  • and, activity to time t be "R".

To find t when R will be "1%" of R_o, then

⇒ R=\frac{1}{100}R_o

As we know,

⇒ R=R_o e^{-\lambda t}

or,

∴ e^{\lambda t}=\frac{R_o}{R}

By putting the values, we get

        =\frac{R_o}{\frac{R}{100} }

        =100

We know that,

Decay constant, \lambda = \frac{ln2}{T_{\frac{1}{2} }}

hence,

⇒ \lambda t=ln100

     t=\frac{ln100}{\lambda}

        =\frac{ln100}{\frac{ln2}{8} }

        =53.15 \ days  

5 0
3 years ago
Other questions:
  • 15 POINTSSS HURRYYY) Carrie is doing an experiment about plants in science class. She has four of the same type of plant. She se
    7·2 answers
  • Two waiters are trying to get through a single door of a kitchen. One pushes on one side of a door 0.567 m from the hinge with a
    5·1 answer
  • A toy train is traveling along a circular track
    13·1 answer
  • A 58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward 3rd base with a velocity of 38.0 m/s.
    7·2 answers
  • Which is a characteristic of an amorphous solid?
    11·1 answer
  • What is the average acceleration of a rocket that travels 400m in 5s if it starts from rest?​
    7·1 answer
  • 3. Define 1 standard kilogram?<br>​
    6·2 answers
  • Please help guy review question.
    5·1 answer
  • How does the suns energy affect the climate of an area
    6·2 answers
  • Please help thanks :)
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!