PLEASE HELPPP! :))))

Which object will be the easiest for a magnet to pull? a 1-gram piece of paper, a 2-gram eraser, a 3-gram steel paper clip, a 4-

Vlad1618 [11]

Steel paper clip because it can be moved by the magnet and it is lighter than the iron nail

6 0

3 years ago

A wheel with moment of inertia 25 kg. m2 and angular velocity 10 rad/s begins to speed up, with angular acceleration 15 rad/sec2

Pani-rosa [81]

Answer:

(A) Angular speed 40 rad/sec

Rotation = 50 rad

(b) 37812.5 J

Explanation:

We have given moment of inertia of the wheel $I=25kgm^2$

Initial angular velocity of the wheel $\omega _0=10rad/sec$

Angular acceleration $\alpha =15rad/sec^2$

(a) We know that $\omega =\omega _0+\alpha t$

We have given t = 2 sec

So $\omega =10+15\times 2=40rad/sec$

Now $\Theta =\omega _0t+\frac{1}{2}\alpha t^2=10\times 2+\frac{1}{2}\times 15\times 2^2=50rad$

(b) After 3 sec $\omega =10+15\times 3=55rad/sec$

We know that kinetic energy is given by $Ke=\frac{1}{2}I\omega ^2=\frac{1}{2}\times 25\times 55^2=37812.5J$

7 0

3 years ago

When attempting to determine the coefficient of kinetic friction, why is it necessary to move the block with constant velocity

Readme [11.4K]

Answer:

Explanation:

In order to measure the coefficient of friction , we apply external force to move the body . When external force comes in motion , we adjust the external force so that it moves with zero acceleration or uniform velocity . In this case external force becomes equal to kinetic frictional force and then net force becomes zero because

net force = mass x acceleration = m x 0 = 0

Now frictional force = μ mg where μ is coefficient of kinetic friction

so F = μ mg where F is external force applied

μ = F / mg

Hence , to make external force equal to frictional force , it is necessary to make acceleration of body zero .

4 0

3 years ago

Before Collision Consider a system to be one train car moving toward another train car at rest When the train cars collide, the

erma4kov [3.2K]

Answer:

2,400kg * m/s

Explanation:

You are missing some information in the question but the rest could be found some where else.

The question gives the masses and starting velocity of each car.

Car 1: m = 600kg and sv = 4m/s

Car 2: m 400kg and sv = 0m/s

Find the momentum of both cars.

Car 1: 600 * 4 = 2400

Car 2: 400 * 0 = 0

Add both.

2400 + 0 = 2400

Best of Luck!

7 0

3 years ago

Read 2 more answers

Which system of measurement has been standardized worldwide for scientific uses?

belka [17]

<h2>Answer: The Systeme international (International System of Units)</h2>

The International System of Units (SI) is used in almost every country in the world (<em>except Burma, Liberia and the United States</em>).

This system was created in 1960 by the 11th General Conference of Weights and Measures in France and is made up of seven basic units:

-Ampere (electric current)

-Kelvin (temperature)

-Second (time)

-Meter (length)

-Kilogram (mass)

-Candela (luminous intensity)

-Mol (amount of substance) *added to the system in 1971

Plus an unlimited number of derived units from the main ones.

7 0

3 years ago