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
Marat540 [252]
3 years ago
14

A ball is dropped off the roof of a tall building. If the ball reaches the ground in 8 seconds, how tall is the building, in met

ers? Round to the nearest whole number (a=9.8 m/s2)
Physics
1 answer:
Ghella [55]3 years ago
5 0

Let <em>b</em> be the height of the building, and <em>y</em> the height of the ball at time <em>t</em>, given by

<em>y</em> = <em>b</em> - 1/2 <em>gt</em>²

where <em>g</em> = 9.8 m/s² is the magnitude of the acceleration due to gravity.

It takes the ball 8 s to reach the ground, at which point <em>y</em> = 0, so that

0 = <em>b</em> - 1/2 (9.8 m/s²) (8 s)²

<em>b</em> = 1/2 (9.8 m/s²) (8 s)²

<em>b</em> = 313.6 m

You might be interested in
If a rocket travels 35,200 miles in 2 hours, what is its speed?
Brrunno [24]

Answer:

Given:

Distance = 35200 miles, time = 2 hr.

So we know = 35200/ 2, = 17600 miles / hr.

8 0
3 years ago
Read 2 more answers
Light rays from stars bend toward smaller angles as they enter Earth's atmosphere. a. Explain why this happens using Snell's law
Grace [21]

Answer:

Following are the answer to this question:

Explanation:

In option (a):

  • The principle of Snells informs us that as light travels from the less dense medium to a denser layer, like water to air or a thinner layer of the air to the thicker ones, it bent to usual — an abstract feature that would be on the surface of all objects. Mostly, on the contrary, glow shifts from a denser with a less dense medium. This angle between both the usual and the light conditions rays is referred to as the refractive angle.  
  • Throughout in scenario, the light from its stars in the upper orbit, the surface area of both the Earth tends to increase because as light flows from the outer atmosphere towards the Earth, it defined above, to a lesser angle.

In option (b):

  • Rays of light, that go directly down wouldn't bend, whilst also sun source which joins the upper orbit was reflected light from either a thicker distance and flex to the usual, following roughly the direction of the curve of the earth.  
  • Throughout the zenith specific position earlier in this thread, astronomical bodies appear throughout the right position while those close to a horizon seem to have been brightest than any of those close to the sky, and please find the attachment of the diagram.

8 0
3 years ago
A baseball is thrown at a 28° angle and an initial velocity of 70 m/s. Assume no air resistance. What is the vertical component
icang [17]

Answer:

answer is 61.8 m/s; 32.9

l am not sure

3 0
2 years ago
I am struggling on this physics question. Brainly is my last hope. Could somebody please provide an answer to this question, wit
Aleks [24]

1) 29.4 N

The force of gravity between two objects is given by:

F=G\frac{Mm}{r^2}

where

G is the gravitational constant

M and m are the masses of the two objects

r is the separation between the centres of mass of the two objects

In this problem, we have

M=5.97\cdot 10^{24} kg (mass of the Earth)

m=3.0 kg (mass of the box)

r=R=6.37\cdot 10^6 m (Earth's radius, which is also the distance between the centres of mass of the two objects, since the box is located at Earth's surface)

Substituting into the equation, we find F:

F=\frac{(6.67\cdot 10^{-11})(5.97\cdot 10^{24})(3.0)}{(6.37\cdot 10^6)^2}=29.4 N

2) g=9.8 m/s^2

Let's now calculate the ratio F/m. We have:

F = 29.4 N

m = 3.0 kg

Subsituting, we find

\frac{F}{m}=\frac{29.4}{3.0}=9.8 N/kg = 9.8 m/s^2

This is called acceleration of gravity, and it is the acceleration at which every object falls near the Earth's surface. It is indicated with the symbol g.

We can prove that this is the acceleration of the object: in fact, according to Newton's second law,

F=ma

where a is the acceleration of the object. Re-arranging,

a=\frac{F}{m}

which is exactly equal to the quantity we have calculated above.

5 0
3 years ago
If you were in charge of designing a wire to carry electricity across your city, state or province, which of
Anon25 [30]

Answer:

Thin, aluminium and buried underground.

Explanation:

When it comes to electrification of a state or province, some characteristics of the wire to use must be considered. This would help to minimize and avoid power loss and wire burns.

i. The wire to use should be thin, and a quite number can be twisted one against the other so as to increase the surface area for heat dissipation.

ii. Aluminium wire is more preferable for this project. It has a high melting point, and reduces energy loss.

iii. Burying the wire underground through an insulator is the best choice, though expensive but would preserve the wire from external influence.

7 0
2 years ago
Other questions:
  • What is the half life of Strontium-90? Explain your answer
    11·2 answers
  • Stars that become black holes have more __________ than stars that become neutron stars
    14·2 answers
  • If the wavelength is tripled, while the speed of the wave is held constant, what happens to the frequency?
    11·1 answer
  • A scientist is giving a demonstration with a Van de Graaff generator in a class about electrostatics. The scientist can detect t
    15·2 answers
  • HELPP PLEASEEE Which issue is not a challenge an organism encounters?
    12·2 answers
  • The micrometer (1 μm) is often called the micron. (a) How many microns make up 3.0 km? (b) How many centimeters equal 3.0 μm? (c
    7·1 answer
  • The number of perpandicular components of a force is<br>​
    7·1 answer
  • Dimas reads that it takes 270 N to lift a firefighter's equipment. If a firefighter does 5400 J of work carrying the equipment u
    13·2 answers
  • A bullet of mass 10g is fired from a gun. The bullet takes 0.003s to move through its barrel and leaves it with a velocity of 30
    5·1 answer
  • A 70.0Kg cyclist Rides a 15.0kg
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!