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
GalinKa [24]
3 years ago
6

Air resistance is a special kind of frictional force that acts on objects as they travel through air. Identify the situation whe

re this frictional force is ABSENT, from the ones given below:

Physics
1 answer:
Nikolay [14]3 years ago
5 0

Answer: A

Explanation:

The air resistance as frictional force will always exist whenever there is motion. And cease to exist whenever there is no motion.

Among all the options, a lamp fixed with a rod from the ceiling experiences no movement. Therefore, this frictional force is ABSENT in that situation.

You might be interested in
A book is thrown downward from the library window with a speed of 2.0\,\dfrac{\text m}{\text s}2.0 s m ​ 2, point, 0, start frac
dem82 [27]

Answer: final Velocity v = 10.2m/s

Explanation:

Final speed v(t) is given as

v(t) = u + at .......1

Where; u = the initial speed

a = acceleration

t = time taken

The total distance travelled d is given as

d = ut + 1/2(at^2)

Given

d = 5.0m

u = 2.0m

a = g = 10m/s2 (acceleration due to gravity)

Substituting into the equation above we have

5 = 2t + 5t^2

5t^2 +2t -5 = 0

Applying the quadratic formula. We have;

t = 0.82s & t = -1.22s

t cannot be negative

t = 0.82s

From equation 1 above

v = 2.0m/s + 10(0.82)m/s

v = 10.2m/s

7 0
3 years ago
Read 2 more answers
The electron's velocity at that instant is purely horizontal with a magnitude of 2 \times 10^5 ~\text{m/s}2×10 ​5 ​​ m/s then ho
Lesechka [4]

Complete question:

At a particular instant, an electron is located at point (P) in a region of space with a uniform magnetic field that is directed vertically and has a magnitude of 3.47 mT. The electron's velocity at that instant is purely horizontal with a magnitude of 2×10​⁵​​ m/s then how long will it take for the particle to pass through point (P) again? Give your answer in nanoseconds.

[<em>Assume that this experiment takes place in deep space so that the effect of gravity is negligible.</em>]

Answer:

The time it will take the particle to pass through point (P) again is 1.639 ns.

Explanation:

F = qvB

Also;

F = \frac{MV}{t}

solving this two equations together;

\frac{MV}{t} = qVB\\\\t = \frac{MV}{qVB} = \frac{M}{qB}

where;

m is the mass of electron = 9.11 x 10⁻³¹ kg

q is the charge of electron = 1.602 x 10⁻¹⁹ C

B is the strength of the magnetic field = 3.47 x 10⁻³ T

substitute these values and solve for t

t = \frac{M}{qB} = \frac{9.11 *10^{-31}}{1.602*10^{-19}*3.47*10^{-3}} = 1.639 *10^{-9}  \ s \ = 1.639 \ ns

Therefore, the time it will take the particle to pass through point (P) again is 1.639 ns.

5 0
3 years ago
Two bullets of the same size, mass and horizontal velocity are fired at identical blocks, only one is made of steel and the othe
tatiyna

Answer and Explanation:

  • Since we're discussing shots, the significant thing is the way the energy is changed over as there is deceleration of the bullet to a halt when it hits something.
  • Kinetic Energy is relative to mass times speed squared, so in reality, the 2 cases given have practically indistinguishable Kinetic energy. The measure of energy is authoritative, so the two cases will do generally a similar harm given, obviously we look at situations when all the kinetic energy is spent.
  • One contrast that will be effectively obvious is that the weapon in the case of heavy bullet will recoil more.  
  • One can consider energy assimilation as force times separation distance, and energy ingestion as a product of force and time.
  • Henceforth, the heavier yet more slow bullet with a similar energy will venture to every part of a similar separation in the engrossing material, but since of bigger force, will take a more drawn out time doing it.
  • It will along these lines, additionally, give a more noteworthy "kick" to the object that absorbs.
8 0
3 years ago
You took a running leap off a high diving platform. You were running at 3.1 m/s and hit the water 2.4 seconds later. How high wa
rusak2 [61]

The distance you free-fall from rest is  D = (1/2) (g) (T²) <== memorize this

Height of the platform = (1/2) (9.8 m/s²) (2.4 sec)²

Height = (4.9 m/s²) (5.76 s²)

Height = (4.9/5.76) meters

Height = 28.2 meters (a VERY high platform ... about 93 ft off the water !)

Without air-resistance, your horizontal speed doesn't change.  It's constant.  Traveling 3.1 m/s for 2.4 sec, you cover (3.1 m/s x 2/4 s) = 7.4 m horizontally.

7 0
4 years ago
A planet orbits a sun in a clockwise elliptical orbit as shown in the diagram below
STatiana [176]

Answer:

Greatest gravitational energy is at "C".

The planet has to do work "against" the field to get to "C".

Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2  must decrease also to get to point C.

3 0
3 years ago
Other questions:
  • Which sentence correctly describes a friction force? A. It acts in the same direction as the motion of an object. B. It acts in
    14·1 answer
  • For a particular reaction, the change in enthalpy is 51kJmole and the activation energy is 109kJmole. Which of the following cou
    6·1 answer
  • A 3.5-cm radius hemisphere contains a total charge of 6.6 × 10–7
    14·1 answer
  • Suppose an object is in orbit around the earth, the earth's gravitational pull some how becomes stronger than the objects forwar
    11·1 answer
  • A transformer has a primary voltage of 115 V and a secondary voltage of 24 V. If the number of turns in the primary is 345, how
    6·1 answer
  • A faulty thermometer reads 2°C when dipped in ice at 0°C and 95°C when dipped in steam at 100°C. What would this thermometer rea
    6·1 answer
  • How to find aceleration
    7·1 answer
  • Physics please help !!
    5·1 answer
  • Energy Transformation
    6·1 answer
  • For stars to form, the temperature of the hydrogen in a nebula must be more than 14 million Kelvin. How did gravitational attrac
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!