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
Anna [14]
3 years ago
9

If a 0.15 kg ball falls and has a KE of 20 J just before striking the ground, from what height did it fall. A. 1.36m B. 3m C. 13

.6m D. 30m
Physics
1 answer:
RUDIKE [14]3 years ago
5 0
According to the conservation of mechanical energy, the kinetic energy just before the ball strikes the ground is equal to the potential energy just before it fell. 

Therefore, we can say KE = PE
We know that PE = m·g·h

Which means KE = m·g·h

We can solve for h:

h = KE / m·g
   = 20 / (0.15 · 9.8) 
   = 13.6m

The correct answer is: the ball has fallen from a height of 13.6m.

You might be interested in
Volcanologists and seismologist are specialzed in what
antiseptic1488 [7]

The answer is:

They are specialized in geology and geophysics

1) Volcanologists are scientific researchers who study the properties of volcanoes and develop the science of predicting volcanic eruptions accurately.

- Volcanoes are the results of fissures in the earth's crust, from which magma, gases, rocks, and ashes can erupt.  


-Volcanic eruptions and their impact on the atmosphere are investigated by specialist geologists known as volcanologists.


A) Volcanologists are scientists who use a variety of sophisticated equipment to measure and analyze volcanic activity, lava, rock, ashes and gases as well as earthquakes caused by eruptions.


B) Also, they measure the magnitude and intensity of explosions, placing them on a scale from 1 to 8 [volcanic explosivity index].  


C)Volcanologists monitor both active and dormant volcanoes to try to predict eruptions and minimize adverse effects on people and their environment.


D)Also, they spend a lot of time collecting and analyzing samples of debris, rocks and other products from extinct volcanoes to gain a better understanding of the processes behind the volcanic activity and the impact former eruptions had in shaping the climate.


2) Seismologists are Earth scientists, specialized in geophysics, who study the genesis and the propagation of seismic waves in geological materials.


-Their research aims at interpreting the geological composition and structures of the Earth. In the case of earthquakes, seismologists evaluate the potential dangers and seek to minimize their impact through the improvement of construction standards.



5 0
3 years ago
Read 2 more answers
A fixed 11.2-cm-diameter wire coil is perpendicular to a magnetic field 0.53 T pointing up. In 0.10 s , the field is changed to
Karolina [17]

Answer:

The average induced emf in the coil is 0.0286 V

Explanation:

Given;

diameter of the wire, d = 11.2 cm = 0.112 m

initial magnetic field, B₁ = 0.53 T

final magnetic field, B₂ = 0.24 T

time of change in magnetic field, t = 0.1 s

The induced emf in the coil is calculated as;

E = A(dB)/dt

where;

A is area of the coil = πr²

r is the radius of the wire coil = 0.112m / 2 = 0.056 m

A = π(0.056)²

A = 0.00985 m²

E = -0.00985(B₂-B₁)/t

E = 0.00985(B₁-B₂)/t

E = 0.00985(0.53 - 0.24)/0.1

E = 0.00985 (0.29)/ 0.1

E = 0.0286 V

Therefore, the average induced emf in the coil is 0.0286 V

3 0
3 years ago
A satellite of mass m completes one revolution around the earth at a constant speed s and radius r.
MAXImum [283]

Answer:

d. The magnitude of the work done by the earth on the satellite is non zero

Explanation:

The work done is equal to the product of the force and the distance moved in the direction of the force, the force and the distance act perpendicular to one another, therefore no work is done in the circular motion of the movement of the earth.

8 0
3 years ago
How do atoms of copper differ from atoms of aluminum? *
Degger [83]

Answer:

The copper atoms are heavier than the aluminum atoms. The copper atoms are smaller than the aluminum atoms so more copper atoms fit in the same volume. 2. Copper is more dense than aluminum.

HOPE THIS HELPS !!!!!

8 0
3 years ago
PHYSICS PLEASE HELP
vaieri [72.5K]

1.)Answer:

The correct answer is C.

Explanation:

Displacement is a vector quantity so it may be either positive or negative. As per convention, acceleration taken as positive when moves downward direction. But, in our case, acceleration towards downward taken as negative, so displacement should also be negative because negative sign only indicate its downward direction.

2.) Answer

The correct answer is C. The time won't change, but horizontal distance will double.

Explanation:

First case

velocity = v = 20 m/s

Height = h = 10 m

We need to calculate time (t) and horizontal distance (x)

using 2nd equation of motion

h = vt + 0.5 gt²

As initial vertical velocity is 0. So

h = 0.5(9.8)t²

It can be see that time does not depends on initial velocity, so it won't change

to calculate x

x = vt

It can be see that horizontal distance will double because depends on velocity.

3.)Question

Illustration:

Day 1: 10 km west and spent night at A.

Day 2: 10 km west and night in a tent B.

Day 3: 20 km west and then they turned around and went back to the home because Jerry left his allergy medicine.

Day 4: 30 km North to the point D.

Answer

The correct answer is C.

Explanation:

On Day 1, Day 2 and Day 3, they move towards west 40 km from home and then turned back to home because Jerry forget his medicine. Thus the total distance is 80 km but the displacement is zero because displacement is the measure from initial to final position. As initial and final position is same at the end of 3rd day so displacement is zero. Fourth day, They move towards north 30 km and hence total distance is 110 km. And total displacement is only 30 km.

4.) Answer:

The correct Answer is A.

Explanation:

To calculate horizontal distance (x), we only need to find the horizontal component of velocity that is

vₓ = v Cos (70°)

vₓ = 41 m/s

As we know that x = vₓ t

So,

x = 41t

5.) Answer

The correct Answer is B.

Explanation:

Displacement is a vector quantity so it depends on direction. As Sally moves 10m forward and then 5m backward, So his total displacement is 5m. While the distance is scalar quantity independent of direction. So the total distance covered by Sally is 15m which is 10m greater than the displacement.  

6.)Answer

The correct answer is A.

Explanation:

Consider

horizontal(h)= 6m

vertical = Xm

Hypotenuse(H) = ?

Angle = 37°

As we know that

H×Cos∅ = h

So,

H = h ÷ Cos(∅)

  = 6 ÷ Cos(37)

H = 7.5 m    

7.) Answer:

The correct answer is D.

Explanation:

In projectile motion, horizontal distance depends on initial velocity and angle with ground. So as the player increase the velocity of the ball, more distance will be covered. As far as he increase the angle upto 45° with the ground, the horizontal distance will increase. That's why the player should increase the ball's initial velocity and kick it at a 45° angle.

8.)Answer:

The correct Answer is B.

Explanation:

Consider

Vector A  = 3m

Vector B  = 4m

Angle = ?

As the angle ∅ is created between vectors C and A.

we know that

tan∅ = vertical ÷ horizontal

tan∅ = 4 ÷ 3

∅ = tan⁻¹ (1.33)

∅ = 53.1°

9.) Answer:

The correct Answer is C.

Explanation:

Projectile motion depends on initial velocity and initial angle with ground. As far as we increase the velocity of the ball, more distance will be covered. As it also depends on angle, So as far as we increase the angle up to 45° with the ground, the horizontal distance will increase. But when the angle is above 45°, increasing angle decrease the horizontal distance.

10.) Answer:

The correct Answer is B.

Explanation:

Given data :

∅ = 20°

initial velocity = 40 m/s

As we need to find the vertical component of velocity

So, initial upward velocity = initial velocity × Sin∅ = 40 × Sin 20°

             initial upward velocity = 13.68 m/s

11.)Answer:

The correct Answer is B.

Explanation:

The projectile motion depends on the angle with the horizontal.As far as we increase the angle up to 45° with the ground, the distance will increase. But when the angle is above 45°, increasing angle decrease the horizontal distance.

12.) Answer:

The correct answer is D.

Explanation:

Given data

Initial speed = V₀ =40 m/s

angle = 60°

g = 9.81 m/s²

First we need to find initial vertical velocity (V)

V = V₀ Sin∅

V = 34.64 m/s

3rd equation of motion

2gh = V₁² - V²

As we need to find maximum height so at highest point vertical final velocity (V₁) = 0

So,

h = V² ÷ 2g

 = 34.64² ÷ 2×9.81

                              h = 61.2 m

13.) Answer:

The correct answer is C.

Explanation:

A bird flying in the air is 3D motion as the bird move up, down, right, left all the possible direction. A leaf falling from a tree is also a 3D motion because a leaf never fall in absolute vertical manner. A lady bug crawling on a soccer ball also 3D. If lady bug crawling on a plane like floor then it is 2D but now lady bug crawling on soccer ball which is in spherical shape so it is also 3D motion. Only train travelling along a track is 2D because train cannot move up and down and the track of train is in a plane. So it is 2D motion.  

6 0
3 years ago
Read 2 more answers
Other questions:
  • A compound machine is made up of one simple machine True or False
    5·2 answers
  • The light of a star that can be seen from Earth is called what? (Apparent or Absolute Magnitude)
    13·1 answer
  • A grocery cart with a mass of 16 kg is pushed at constant speed along an aisle by a force fp = 12 n which acts at an angle of 17
    13·2 answers
  • Atmospheric pressure is reported in a variety of units depending on local meteorological preferences. In many European countries
    9·1 answer
  • Most cars have a coolant reservoir to catch radiator fluid that may overflow when the engine is hot. A radiator is made of coppe
    14·1 answer
  • PLEASE SOLVE QUICKLY!!!<br> Solve for A, B, and C from graph
    7·1 answer
  • What is the kinetic energy of a 1200 kg roller coaster that is moving with a speed of 24.0 m/s. ?
    14·1 answer
  • What happens if two plates move away from each other?
    15·2 answers
  • Calculate the moment of 3kg and 20cm away from the pivot​
    8·1 answer
  • A coin is dropped from a height of 421 m. calculate the velocity of the coin after 3 s​
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!