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
babunello [35]
3 years ago
15

Responding to an alarm, a 765-N firefighter slides down a pole to the ground floor, 3.5 m below. The firefighter starts at rest

and lands with a speed of 3.8 m/s . Find the average force exerted on the firefighter by the pole.
Physics
1 answer:
Afina-wow [57]3 years ago
4 0

Answer:

Explanation:

Let acceleration of fall be a .

v² = u² + 2as

v = 3.8 m /s

u = 0

s = 3.5 m

3.8² = 0 + 2 x a x 3.5

a = 2.06 m /s²

Since this acceleration is less than g , an upward force is acting on the firefighter in the form of friction . Let this force be F . Let mass of the firefighter be m .

m = 765 / 9.8

= 78.06 kg

mg - F = ma

765 - F = 78.06 x 2.06

765 - F = 160.8

F = 604.2 N .

You might be interested in
Form a hypothesis about how deeply water could erode and about how deeply glaciers could erode
Softa [21]
A hypothesis is an educated guess. It's your own opinion!
8 0
4 years ago
The number of neutrons is equal to the atomic number<br> O A True<br> B. False
jonny [76]

The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number. Therefore, it is true!

6 0
3 years ago
Read 2 more answers
A young girl slides down a rope. As she slides
hodyreva [135]

Answer:

The girl will move with constant velocity

Explanation:

If after a certain time t_0 the velocity of the girl is v_0 =gt_0 and the upward force on the girl due to rope is mg ,where g is gravitational acceleration. Then the girl will move down with the constant velocity v_0 .

The girl will move with constant velocity,as explained above.

6 0
3 years ago
The elements least likely to form bonds are found in which group?<br> O 15<br> O 16<br> 017<br> O 18
12345 [234]
The answer is group 18.

Explanation:
Group 18 is known as the Noble Gases. They are the most stable elements because they have a full outer shell of valence electrons, so they have no need to bond with other elements.
7 0
3 years ago
Read 2 more answers
wheel rotates from rest with constant angular acceleration. Part A If it rotates through 8.00 revolutions in the first 2.50 s, h
Alex73 [517]

Answer:

x2 = 64 revolutions.

it rotate through 64 revolutions in the next 5.00 s

Explanation:

Given;

wheel rotates from rest with constant angular acceleration.

Initial angular speed v = 0

Time t = 2.50

Distance x = 8 rev

Applying equation of motion;

x = vt +0.5at^2 ........1

Since v = 0

x = 0.5at^2

making a the subject of formula;

a = x/0.5t^2 = 2x/t^2

a = angular acceleration

t = time taken

x = angular distance

Substituting the values;

a = 2(8)/2.5^2

a = 2.56 rev/s^2

velocity at t = 2.50

v1 = a×t = 2.56×2.50 = 6.4 rev/s

Through the next 5 second;

t2 = 5 seconds

a2 = 2.56 rev/s^2

v2 = 6.4 rev/s

From equation 1;

x = vt +0.5at^2

Substituting the values;

x2 = 6.4(5) + 0.5×2.56×5^2

x2 = 64 revolutions.

it rotate through 64 revolutions in the next 5.00 s

5 0
4 years ago
Other questions:
  • The wheel of a stationary exercise bicycle at your gym makes one rotation in 0.670 s. Consider two points on this wheel: Point P
    14·1 answer
  • A world-class tennis player can serve a tennis ball at 130 mi/h mi/h (about 58 m/s m/s ). The length of a tennis court is 78 ft
    10·1 answer
  • Sedimentary rocks are the only rocks that can potentially containa.fossils.c.fractures.b.minerals.d.faults. Please select the be
    15·2 answers
  • What happens when a electron and a proton get close together?
    15·1 answer
  • The hubbles telescopes orbit is 5.6 x10 ^5 meters above earths suface. the telescope has a mass os 1.1 x10^4 kilograms. earth ex
    15·1 answer
  • What are the chances that radio transmissions from Earth or messages sent on distant space probes will ever be received by livin
    14·1 answer
  • A parallel plate capacitor has two plates has a separation d. If I charge it with a +Q and a ????Q on the two plates, respective
    8·1 answer
  • Does a ball rolling on an inclined plane have the same acceleration on the way up as it does on the way down?
    11·1 answer
  • A truck accelerates on a highway from rest to 216 m/s in 10s. What is the magnitude of acceleration?
    7·1 answer
  • *example included* Two uncharged spheres are separated by 3.50 m. If 1.30 ✕ 10¹² electrons are removed from one sphere and place
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!