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
ohaa [14]
3 years ago
7

The objects listed are placed at the top of a ramp and roll down to the bottom without slipping. Assuming that there is no air r

esistance, rank them in order from fastest average rolling speed to slowest. a. large marble b. basteball c. manhole cover d. wedding ring
Physics
1 answer:
Thepotemich [5.8K]3 years ago
7 0

Explanation:

For each object, the initial potential energy is converted to rotational energy and translational energy:

PE = RE + KE

mgh = ½ Iω² + ½ mv²

For the marble (a solid sphere), I = ⅖ mr².

For the basketball (a hollow sphere), I = ⅔ mr².

For the manhole cover (a solid cylinder), I = ½ mr².

For the wedding ring (a hollow cylinder), I = mr².

If we say k is the coefficient in each case:

mgh = ½ (kmr²) ω² + ½ mv²

For rolling without slipping, ωr = v:

mgh = ½ kmv² + ½ mv²

gh = ½ kv² + ½ v²

2gh = (k + 1) v²

v² = 2gh / (k + 1)

The smaller the value of k, the higher the velocity.  Therefore:

marble > manhole cover > basketball > wedding ring

You might be interested in
Which factors would increase heating of Earth, and which factors would decrease it
loris [4]

Answer:

So as sunlight continued to enter the box and the walls continued to warm, heat built up inside and increased the temperature.

4 0
2 years ago
Read 2 more answers
A 98-kg fullback is running along at 8.6 m / s when a 76-kg defensive back running in the same direction at 9.8 m / s jumps on h
algol13
The total momentum before and after the collision must be conserved.

The total momentum before the collision is:
p_i = m_1 v_1 + m_2 v_2
where m1 and m2 are the masses of the two players, and v_1 and v_2 their initial velocities. Both are considered with positive sign, because the two players are running toward the same direction.

The final momentum is instead
p_f = (m_1+m_2)v_f
because now the two players are moving together with a total mass of (m1+m2) and final speed vf.

By requiring that the momentum is conserved
p_i=p_f
we  can calculate vf, the post-collision speed:
m_1 v_1 + m_2 v_2 = (m_1+m_2)v_f
v_f =  \frac{m_1 v_1 + m_2 v_2}{m_1 +m_2}= \frac{(98 kg)(8.6 m/s)+(76 kg)(9.8m/s)}{98 kg+76 kg}=9.1 m/s
and the direction is the same as the direction of the players before the collision.
6 0
3 years ago
(a) calculate the speed of a proton after it accelerates from rest through a potential difference of 215 v. m/s (b) calculate th
bija089 [108]
<span>The proton differs from the electron in sign although they have the same value. Like the electron, a proton will gain 215 electron-volts of eV in Kinetic energy. So 1.602Ă—10^-19 J * 215 = 344.43 * 10^(-19) J. But K. E. = mv^2 / 2, so v^2 = 2 * K.E/m. The mass of a proton is 1.673 * 10^-27 kg. So v = âš(2 * 344.43 * 10^(-19))/1.673Ă—10^-27 = 688.86 * 10^(-19)/1.673Ă—10^(-27) = 411.75 * 10^(-19-(-27)) = âš411.75 * 10^(8) = 202196.56 Also for the electron we have v^2 = 2 * K.E/m but here mass, m, = 9.109 * 10^-31 kg. So we have v = âš(2 * 344.43 * 10^(-19)) / 9.109 * 10^-31 = 688.86 * 10^(-19)/ 9.109 * 10^-31 = 75.624 * 10^(-19 - (-31)) = 75.624 * 10^(21) and v = 2.749 * 10^11</span>
3 0
3 years ago
The earliest known records describing electric charge involve the use of _____.
blondinia [14]
Amber is the answer to this question
5 0
3 years ago
Read 2 more answers
A proton moves perpendicular to a uniform magnetic field B at a speed of 2.30 107 m/s and experiences an acceleration of 2.50 10
Katen [24]

Answer:

B = 6.18 10⁻⁶ T  

the magnetic field is in the negative direction of the y axis

Explanation:

The magnetic force is given by

         F = q v x B

as in the exercise indicate that the velocities perpendicular to the magnetic field,

         F = q v B

Newton's second law is

         F = m a

let's substitute

         q v B = m a

         B = m a / q v

let's calculate

         B = 9.1 10⁻³¹ 2.50 10¹³ / (1.6 10⁻¹⁹ 2.30 10⁷)

         B = 6.18 10⁻⁶ T

The direction of the field can be obtained with the right hand rule, where the thumb points in the direction of the velocity, the fingers extended in the direction of the magnetic field and the palm in the direction of the force for a positive charge.

In the exercise indicate that the velocity is the z axis

the acceleration and therefore the force in the x axis

therefore the magnetic field is in the negative direction of the y axis

7 0
2 years ago
Other questions:
  • The spring is now compressed so that the unconstrained end moves from x=0 to x=L. Using the work integral W=∫xfxiF⃗ (x⃗ )⋅dx⃗ ,
    6·1 answer
  • A ledge on a building is 20 m above the ground. A taut rope attached to a 4.0 kg can of paint sitting on the ledge passes up ove
    15·1 answer
  • One major advantage of alternating current over direct current is that you can use alternating current with a device known as a
    11·1 answer
  • 14. How are position and speed useful for describing the motion of an object?
    14·1 answer
  • N/a<br>n/a<br>nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn
    7·1 answer
  • Puck 1 is moving 10 m/s to the left and puck 2 is moving 8 m/s to the right. They have the same mass, m.
    6·1 answer
  • A 2 kg ball of clay moving at 35 m/s strikes a 10 kg box initially at rest. What is the velocity of the box after the collision?
    9·1 answer
  • What is the purpose of radio waves?
    15·2 answers
  • A mass is attached to the end of a spring and set into oscillation on a horizontal frictionless surface by releasing it from a c
    6·1 answer
  • A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the sub
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!