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
liberstina [14]
3 years ago
15

A pole-vaulter is nearly motionless as he clears the bar, set 4.2 m above the ground. He then falls onto a thick pad. The top of

the pad is 80 cm above the ground, and it compresses by 50 cm as he comes to rest. What is the magnitude of his acceleration as he comes to rest on the pad?
Physics
1 answer:
Mandarinka [93]3 years ago
5 0

initial height of the Pole - vaulter = 4.2 m

now when he reached the top of the pad his height is 80 cm

so the total displacement of the person will be = 4.2 - 0.8 = 3.4 m

now we can use kinematics to find the speed just before he touch the pad

v_f^2 - v_i^2 = 2 a d

v_f^2 - 0 = 2*9.8*3.4

v_f^2 = 66.64

v_f = 8.16 m/s

now when he compressed on pad the distance after which he will stop is 50 cm

so now again using kinematics we can say

v_f^2 - v_i^2 = 2 a d

0 - 8.16^2 = 2*a*0.50

a = -66.64 m/s^2

so it is acceleration by -66.64 m/s^2

You might be interested in
A projectile is launched at ground level with an initial speed of 54.5 m/s at an angle of 35.0° above the horizontal. It strikes
Alchen [17]
<h2>Answer: x=125m, y=48.308m</h2>

Explanation:

This situation is a good example of the projectile motion or parabolic motion, in which we have two components: x-component and y-component. Being their main equations to find the position as follows:

x-component:

x=V_{o}cos\theta t   (1)

Where:

V_{o}=54.5m/s is the projectile's initial speed

\theta=35\° is the angle

t=2.80s is the time since the projectile is launched until it strikes the target

x  is the final horizontal position of the projectile (the value we want to find)

y-component:

y=y_{o}+V_{o}sin\theta t-\frac{gt^{2}}{2}   (2)

Where:

y_{o}=0  is the initial height of the projectile (we are told it  was launched at ground level)

y  is the final height of the projectile (the value we want to find)

g=9.8m/s^{2}  is the acceleration due gravity

Having this clear, let's begin with x (1):

x=(54.5m/s)cos(35\°)(2.8s)   (3)

x=125m   (4)  This is the horizontal final position of the projectile

For y (2):

y=0+(54.5m/s)sin(35\°)(2.8s)-\frac{(9.8m/s^{2})(2.8s)^{2}}{2}   (5)

y=48.308m   (6)  This is the vertical final position of the projectile

4 0
3 years ago
The sun's energy begins as what form of energy?
blagie [28]

Answer:

nuclear energy.............

4 0
3 years ago
Can you please summarise this, because I can't get the topic
wlad13 [49]
An electric circuit is anything in which electric current flows. Typically it refers to things with wiring like the electronics in your phone, but it can be made of anything that conducts electricity.

Say you have a battery, it basically has a bunch of electrons under a potential (think of gas in a tank under pressure), but the only way for the electrons to move is to move through a conductor, which are molecules with loosely held electrons. If you take a copper wire and touch each end to the two terminals you’ve completed an electric circuit because the electrons can now flow. But you can also put things partway through the wire like a lightbulb, which when the electrons run through it generates light.
4 0
3 years ago
Gold-leaf electroscope uses
Kruka [31]
-identifies an electric charge 
-it can identify its polarity (positive or negative) if you compare it to a charge that you already know
-can identify the magnitude of a charge (how big of a charge it is)
7 0
3 years ago
The air is soundproof??
Svet_ta [14]
Not possible. The air is actually able to travel sound throughout itself without any difficulties. I believe, air actually brings sound closer to the people farther away ; It really helps to stretch sound.
7 0
3 years ago
Read 2 more answers
Other questions:
  • The following is a chemical reaction for _______ with ozone.
    11·2 answers
  • If the velocity of an object changes from 15 m/s during a time interval of 4s what is the acceleration of the object
    7·1 answer
  • Tech A says motor action occurs through the interaction of the magnetic fields of the field coils and the armature, which causes
    7·1 answer
  • A rock is projected from the edge of the top of a building with an initial velocity of 12.2 m/s at an angle of 53° above the hor
    6·1 answer
  • Light travels through a substance at 1.97 x 10^8 m/s. What is the index of the liquid? What type of liquid is it?
    13·2 answers
  • Plz help...Thanks.
    6·1 answer
  • What might cause a theory to change over time?
    13·1 answer
  • The pressure at the bottom of a glass filled with water (r 5 1 000 kg/m3 ) is P. The water is poured out and the glass is filled
    12·1 answer
  • In which type of mixture can different parts be seen?
    10·1 answer
  • Carbon has 4 valence electrons. Hydrogen has 1 valence
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!