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
lina2011 [118]
3 years ago
7

Starting from rest, a 1.8 x 10^-4 kg flea springs straight upward. While the flea is pushing off from the ground, the ground exe

rts an average upward force of 0.42 N on it. This force does +2.7 x 10^-4 J of work on the flea. (a) What is the flea's speed when it leaves the ground? (b) How far upward does the flea move while it is pushing off? Ignore both air resistance and the flea's weight.
Physics
1 answer:
bazaltina [42]3 years ago
4 0

Answer:

a)

1.73 m/s

b)

6.43 x 10⁻⁴ m

Explanation:

m = mass of the flea = 1.8 x 10⁻⁴ kg

v₀ = initial speed of the flea = 0 m/s

v = final speed of the flea

W = work done by the force on the flea = 2.7 x 10⁻⁴ J

Using work-change in kinetic energy, Work done is given as

W = (0.5) m (v² - v₀²)

Inserting the values

2.7 x 10⁻⁴ = (0.5) (1.8 x 10⁻⁴) (v² - 0²)

v = 1.73 m/s

b)

d = distance moved by the flea while pushing off

F = Upward force applied on the flea by ground = 0.42 N

Work done is also given as

W = F d

2.7 x 10⁻⁴ = (0.42) d

d = 6.43 x 10⁻⁴ m

You might be interested in
An object weighing 4 newtons swings on the end of a string as a simple pendulum. At the bottom of the swing, the tension in the
Anit [1.1K]

Answer:

(B) 0.5 g

Explanation:

Newton's second law says ∑  F i = m a .

the rate of change in momentum of a body is proportional to the force applied on the body.

f∝ma

f=kma

were k is constant and equal to 1

The centripetal acceleration is an acceleration.

the tension on the swing and object weight goes to the left hand side while the centripetal acceleration goes to the right handside

At the bottom of the swing, ΣF = FT – mg = mac;

notice that the tension in the swing is 1.5 times the weight of the object

we can write

1.5mg – mg = mac,

0.5mg = mac

0.5 g=ac

8 0
2 years ago
Read 2 more answers
Who was the most famous member of the Underground Railroad?
MArishka [77]

Answer:

Harriet Tubman

Explanation:

7 0
2 years ago
Read 2 more answers
Match the vocabulary terms to their definitions. ​
Vilka [71]

See the attached picture:

8 0
3 years ago
Read 2 more answers
An explorer is caught in a whiteout (in which the snowfall is so thick that the ground cannot be distinguished from the sky) whi
mel-nik [20]

Answer:

Explanation:

All the displacement will be converted into vector, considering east as x axis and north as y axis.

5.3 km north

D = 5.3 j

8.3 km at 50 degree north of east

D₁= 8.3 cos 50 i + 8.3 sin 50 j.

= 5.33 i + 6.36 j

Let D₂ be the displacement which when added to D₁ gives the required displacement D

D₁ + D₂ = D

5.33 i + 6.36 j + D₂ = 5.3 j

D₂ = 5.3 j - 5.33i - 6.36j

= - 5.33i - 1.06 j

magnitude of D₂

D₂²= 5.33² + 1.06²

D₂ = 5.43 km

Angle θ

Tanθ = 1.06 / 5.33

= 0.1988

θ =11.25 ° south of due west.

4 0
3 years ago
A .5 kg air puck moves to the right at 3 m/s, colliding with a 1.5kg air puck that is moving to the left at 1.5 m/s.
arlik [135]

Answer:

part (a) v = 1.7 m/s towards right direction

part (b) Not an elastic collision

part (c) F = -228.6 N towards left.

Explanation:

Given,

  • Mass of the first puck = m_1\ =\ 5\ kg
  • Mass of the second puck = m_2\ =\ 3\ kg
  • initial velocity of the first puck = u_1\ =\ 3\ m/s.
  • Initial velocity of the second puck = u_2\ =\ -1.5\ m/s.

Part (a)

Pucks are stick together after the collision, therefore the final velocities of the pucks are same as v.

From the conservation of linear momentum,

m_1u_1\ +\ m_2u_2\ =\ (m_1\ +\ m_2)v\\\Rightarrow v\ =\ \dfrac{m_1u_1\ +\ m_2u_2}{m_1\ +\ m_2}\\\Rightarrow v\ =\ \dfrac{5\times 3\ -\ 1.5\times 1.5}{5\ +\ 1.5}\\\Rightarrow v\ =\ 1.7\ m/s.

Direction of the velocity is towards right due to positive velocity.

part (b)

Given,

Final velocity of the second puck = v_2\ =\ 2.31\ m/s.

Let v_1 be the final velocity of first puck after the collision.

From the conservation of linear momentum,

m_1u_1\ +\ m_2u_2\ +\ m_1v_1\ +\ m_2v_2\\\Rightarrow v_1\ =\ \dfrac{m_1u_1\ +\ m_2u_2\ -\ m_2v_2}{m_1}\\\Rightarrow v_1\ =\ \dfrac{5\times 3\ -\ 1.5\times 1.5\ -\ 1.5\times 2.31}{5}\\\Rightarrow v_1\ =\ 1.857\ m/s.

For elastic collision, the coefficient of restitution should be 1.

From the equation of the restitution,

v_1\ -\ v_2\ =\ e(u_2\ -\ u_1)\\\Rightarrow e\ =\ \dfrac{v_1\ -\ v_2}{u_2\ -\ u_1}\\\Rightarrow e\ =\ \dfrac{1.857\ -\ 2.31}{-1.5\ -\ 3}\\\Rightarrow e\ =\ 0.1\\

Therefore the collision is not elastic collision.

part (c)

Given,

Time of impact = t = 25\times 10^{-3}\ sec

we know that the impulse on an object due to a force is equal to the change in momentum of the object due to the collision,

\therefore I\ =\ \ m_1v_1\ -\ m_1u_1\\\Rightarrow F\times t\ =\ m_1(v_1\ -\ u_1)\\\Rightarrow F\ =\ \dfrac{m_1(v_1\ -\ u_1)}{t}\\\Rightarrow F\ =\ \dfrac{5\times (1.857\ -\ 3)}{25\times 10^{-3}}\\\Rightarrow F\ =\ -228.6\ N

Negative sign indicates that the force is towards in the left side of the movement of the first puck.

3 0
3 years ago
Other questions:
  • Anna learned that every magnet has a north and a south end called poles. One day, while she is playing with magnets she notices
    13·2 answers
  • 5. Would the bruises on the dead man have formed in the epithelia
    8·1 answer
  • A runner sprints around a circular track of radius 130 m at a constant speed of 7 m/s. The runner's friend is standing at a dist
    11·1 answer
  • A child operating a radio-controlled model car on a dock accidentally steers it off the edge. The car's displacement 0.91 s afte
    15·1 answer
  • According to the electromagnetic spectrum,
    11·2 answers
  • If fluorine was in ionic compounds with ions of each of the following atoms, how many fluorines would be needed?
    14·1 answer
  • A 125 g pendulum bob hung on a string of length 35 cm has the same period as when the bob is hung from a spring and caused to os
    11·1 answer
  • The physical (natural) laws which establish how things work can be investigated by the scientific method. True or False
    12·2 answers
  • I WILL GIVE BRAINLIEST
    6·2 answers
  • Viruses use the energy of the ______ cells to reproduce themselves​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!