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
Alborosie
3 years ago
13

A disk-shaped merry-go-round of radius 2.13 m and mass 175 kg rotates freely with an angular speed of 0.651 rev/s. A 55.4 kg per

son running tangentially to the rim of the merry-go-round at 3.51 m/s jumps onto its rim and holds on. Before jumping on the merry-go-round, the person was moving in the same direction as the merry-go-round's rim.
Calculate the final kinetic energy for this system.
Physics
1 answer:
GREYUIT [131]3 years ago
8 0

Answer:

Explanation:

To find out the angular velocity of merry-go-round after person jumps on it , we shall apply law of conservation of ANGULAR momentum

I₁ ω₁ + I₂ ω₂ = ( I₁  + I₂ ) ω

I₁ is moment of inertia of disk , I₂ moment of inertia of running person , I is the moment of inertia of disk -man system , ω₁ and ω₂ are angular velocity of disc and man .

I₁ = 1/2 mr²

= .5 x 175 x 2.13²

= 396.97 kgm²

I₂ = m r²

= 55.4 x 2.13²

= 251.34 mgm²

ω₁ = .651 rev /s

= .651 x 2π rad /s

ω₂ = tangential velocity of man / radius of disc

= 3.51 / 2.13

= 1.65 rad/s

I₁ ω₁ + I₂ ω₂ = ( I₁  + I₂ ) ω

396.97 x  .651 x 2π + 251.34 x 1.65 = ( 396.97 + 251.34 ) ω

ω = 3.14 rad /s

kinetic energy = 1/2 I ω²

= 3196 J

You might be interested in
¿Hacia dónde se moverá el burro que se quiere sacar del corral jalándolo dos personas? La primer persona jala con 8 unidades de
dimaraw [331]

Answer:

sim eu também preciso desta respota

7 0
2 years ago
A 2kg Book is sitting on a table.a 10n Force is pulling to the right.a 3n Force is pulling to the left what is the net force act
salantis [7]


The net force = sum of all forces acting on the body



If we take left side as -ve and right side as +ve,
then,

The net force here would be equal to,
10N + (- 3N)
= 7N.


Therefore, a net force of +7N ( + indicates it's moving towards right) is acting on the book of mass 2kg.


4 0
3 years ago
The two cyclists travel at the same speed on level ground. They approach a low hill and decide to coast up instead of hard pedal
Sergeeva-Olga [200]

Answer:

  • <u>Option-(E): </u>Bike B; its wheels have a smaller moment of inertia.                                                                                                                                                                                                                                                                              

Explanation:

  • The two cyclists travel at the same speed on level ground, as they approach a low hill and decide to coast up instead of hard pedaling. At the top of the hill, as bike "B" will have a larger speed, as compared to the bike "A".Due, to the effect of having smaller moment of inertia, I=m×r².
  • Having no friction nor air resistance, and all the wheels roll on the ground without slipping. While, the B have larger speed,v due to the fact that bike "B" will have a larger speed,"v" as compared to the bike "A".
3 0
3 years ago
If an electronin an electron beam experiences a downward force of 2.0x10^-14N while traveling in a magnetic field of 8.3x10^-2T
Anni [7]

Answer:

Explanation:

Given that,

Force is downward I.e negative y-axis

F = -2 × 10^-14 •j N

Magnetic field is westward, +x direction

B = 8.3 × 10^-2 •i T

Charge of an electron

q = 1.6 × 10^-19C

Velocity and it direction?

Force in a magnetic field is given as

F = q(V×B)

Angle between V and B is 270, check attachment

The cross product of velocity and magnetic field

F =qVB•Sin270

2 × 10^-14 = 1.6 × 10^-19 × V × 8.3 × 10^-2

Then,

v = 2 × 10^-14 / (1.6 × 10^-19 × 8.3 × 10^-2)

v = 1.51 × 10^6 m/s

Direction of the force

Let x be the direction of v

-F•j = v•x × B•i

From cross product

We know that

i×j = k, j×i = -k

j×k =i, k×j = -i

k×i = j, i×k = -j OR -k×i = -j

Comparing -k×i = -j to given problem

We notice that

-F•j = q ( -V•k × B×i)

So, the direction of V is negative z- direction

V = -1.51 × 10^6 •k m/s

6 0
2 years ago
If 1.8 amp flows through a 40 ohm resistor, the voltage across the resistor is :
GenaCL600 [577]

Answer:

72 volts.

Explanation:

To solve this, we have to use the Ohm's law.

The ohm's law tells us that the voltage drop of a resistor is directly proportional to the current applied to the conductor.

V=I*R

in this case the current is 1.8 amps and the resistor is 40 ohm

V=1.8*40

so

V=72 volts.

5 0
3 years ago
Other questions:
  • A long, straight wire lies in the plane of a circular coil with a radius of 0.018 m. the wire carries a current of 5.6 a and is
    14·1 answer
  • A 1.41 µF capacitor charged to 51 V and a 2.49 µF capacitor charged to 31 V are connected to each other, with the two positive p
    14·2 answers
  • An inductor has inductance of 0.260 H and carries a current that is decreasing at a uniform rate of 18.0 mA/s.
    12·1 answer
  • How is magnetism important to our evolution?
    12·1 answer
  • A plank of length L and mass M hangs from an axle passing through one end. The other end is allowed to hang down so that it just
    5·1 answer
  • A small sphere is hung by a string from the ceiling of a van. When the van is stationary, the sphere hangs vertically. However,
    10·1 answer
  • SPEED AND VELOCITY<br> Plz someone help
    12·1 answer
  • A submarine is at an ocean depth of 3.00 km.
    12·1 answer
  • Which are two characteristics of a proton
    6·2 answers
  • The _____ of an object consists of its speed and direction.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!