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
UNO [17]
3 years ago
9

Two red blood cells each have a mass of 9.05×10−14 kg and carry a negative charge spread uniformly over their surfaces. The repu

lsion arising from the excess charge prevents the cells from clumping together. One cell carries −2.10 pC and the other −3.30 pC, and each cell can be modeled as a sphere 3.75×10−6 m in radius. If the red blood cells start very far apart and move directly toward each other with the same speed, what initial speed would each need so that they get close enough to just barely touch? Assume that there is no viscous drag from any of the surrounding liquid.
Physics
1 answer:
Nastasia [14]3 years ago
6 0

Answer:

v = 302.923 m/s

Explanation:

We can answer this question using conservation of energy. Since there is no energy loss (e.g. no viscous drag) the energy when they are far apart and the energy when they barely touch must be the same.

The initial energy must be equal to the sum of their kinetic energies, since they are far apart to feel their electrical interaction.

Ei = (1/2)mv1^2 + (1/2)m*v2^2

Let us consider that they move with the same speed:

Ei = mv^2

If we consider the case when they barely touch, there won't be any kinetic energy, just pure electromagnetic energy:

Ef = k q1q2/(r1+r2) = k q1q2/(2r1)

Since Ei = Ef

v^2 = (k/m) q1q2/(2r1)

where

  k = 8.98755 x10^9 Nm^2/C^2

  m = 9.05 x10^-14 kg

  q1 = −2.10 pC

  q2 = −3.30 pC

  r1 = 3.75×10^−6 m

v^2 = 91762.4 m^2/s^2

v = 302.923 m/s

You might be interested in
A satellite is in orbit 36000km above the surface of the earth. Its angular velocity is 7.27*10^-5 rad/s. What is the velocity o
bagirrra123 [75]

Answer:

v = 3.08 km/s

Explanation:

Given that,

The angular velocity of the satellite = \omega=7.27\times 10^{-5} rad/s

A satellite is in orbit 36000km above the surface of the earth.

The radius of the earth is 6400 km

Let v is the velocity of the satellite. It can be calculated as :

v=r\omega\\\\v=(36000\times 10^3+6400\times 10^3)\times 7.27\times 10^{-5}\\\\v=3082.48\ m/s\\\\v=3.08\ km/s

So, the velocity of the satellite is 3.08 km/s.

6 0
3 years ago
1. A negatively charged rod is moved near the top of a positively charged electroscope. What
Xelga [282]

Answer:

A) Moves closer together

7 0
3 years ago
E14. A ball rolls off a table with a horizontal velocity of 5 m/s. If
Shkiper50 [21]

a) Vertical velocity: 5.9 m/s

b) Horizontal velocity: 5 m/s

Explanation:

a)

The motion of the ball is the motion of a projectile, which consists of two independent motions:

- A uniform motion (constant velocity) along the horizontal direction)

- A uniformly accelerated motion (constant acceleration) along the vertical direction

Here we want to find the vertical component of the ball's velocity. This can be done by using the suvat equation for the vertical motion:

v_y = u_y +gt

where:

v_y is the vertical velocity at time t

u_y=0 is the initial vertical velocity (zero because the ball has been thrown horizontally)

g=10 m/s^2 is the acceleration of gravity (here we take downward as positive direction)

Substituting t = 0.6 s, which is the total time of flight, we find the vertical velocity of the ball just before it hits the ground:

v_y=0+(9.8)(0.6)=5.9 m/s

b)

The motion along the vertical direction is an accelerated motion, because there is a force (the force of gravity) acting on the ball and that it causes an acceleration in the ball.

However, there are no forces acting in the horizontal direction on the ball (if we neglect the air resistance): this means that the acceleration of the ball in the horizontal direction is zero.

As a consequence, this also means that the horizontal component of the ball's velocity is constant during the motion.

Since the ball was thrown from the table with an initial horizontal velocity of 5 m/s, this means that the horizontal velocity of the ball just before it hits the floor is still

v_x =  5 m/s

8 0
3 years ago
Which has more KE, a large truck moving at 50m/s or a bicycle moving at 10m/s?
klio [65]
The truck has more KE than the bike
8 0
3 years ago
Read 2 more answers
If a 1000-pound capsule weighs only 165 pounds on the moon, how much work is done in propelling this capsule out of the moon's g
Bas_tet [7]

Answer:

  W = 1,307 10⁶ J

Explanation:

Work is the product of force by distance, in this case it is the force of gravitational attraction between the moon (M) and the capsule (m₁)

              F = G m₁ M / r²

              W = ∫ F. dr

              W = G m₁ M ∫ dr / r²

we integrate

             W = G m₁ M (-1 / r)

                 

We evaluate between the limits, lower r = R_ Moon and r = ∞

           W = -G m₁ M (1 /∞ - 1 / R_moon)

            W = G m1 M / r_moon

Body weight is

             W = mg

             m = W / g

The mass is constant, so we can find it with the initial data

For the capsule

            m = 1000/32 = 165 / g_moon

            g_moom = 165 32/1000

            .g_moon = 5.28 ft / s²

I think it is easier to follow the exercise in SI system  

           W_capsule = 1000 pound (1 kg / 2.20 pounds)

           W_capsule = 454 N

           W = m_capsule g

           m_capsule = W / g

           m = 454 /9.8

           m_capsule = 46,327 kg

Let's calculate

          W = 6.67 10⁻¹¹ 46,327   7.36 10²² / 1.74 10⁶

          W = 1,307 10⁶ J

7 0
3 years ago
Other questions:
  • A. Which of the four thermal processes describes the pressure-volume relationship at a constant temperature?
    8·2 answers
  • Electrical Safety: What should you do to a hot plate before turning it on? More than one answer may be correct. Check that the l
    6·1 answer
  • You stare at a bright red screen for so long that your red cones become saturated and no longer function. The red screen is then
    6·2 answers
  • PLEASE HELP TIME SENSITIVE:)
    10·2 answers
  • Water is pouring into an inverted cone at the rate of 3.14 cubic meters per minute. The height of the cone is 10 meters and the
    10·1 answer
  • A whale swims due east for a distance of 6.9 km, turns around and goes due west for 1.8 km, and finally turns around again and h
    11·1 answer
  • (c) The ball leaves the tennis player's racket at a speed of 50 m/s and travels a
    7·1 answer
  • What is sin for the given right triangle?
    12·2 answers
  • In an experiment, a disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small spher
    7·1 answer
  • A father (75 kg) was standing watching TV, minding his own business when one of his kids (20 kg) approached him at 2m/s heading
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!