11)

Briefly answer the following questions. a) A clock is mounted on the wall. As you look at it, what is the direction of the angul

Lelu [443]

Answer:

Explanation:

a ) The direction of angular velocity vector of second hand will be along the line going into the plane of dial perpendicular to it.

b ) If the angular acceleration of a rigid body is zero, the angular velocity will remain constant.

c ) If another planet the same size as Earth were put into orbit around the Sun along with Earth the moment of inertia of the system will increase because the mass of the system increases. Moment of inertia depends upon mass and its distribution around the axis.

d ) Increasing the number of blades on a propeller increases the moment of inertia , because both mass and mass distribution around axis of rotation increases.

e ) It is not possible that a body has the same moment of inertia for all possible axes because a body can not remain symmetrical about all axes possible. Sphere has same moment of inertia about all axes passing through its centre.

f ) To maximize the moment of inertia of a flywheel while minimizing its weight, the shape and distribution of mass should be such that maximum mass of the body may be situated at far end of the body from axis of rotation . So flywheel must have thick outer boundaries and this should be

attached with axis with the help of thin rods .

g ) When the body is rotating at the same place , its translational kinetic energy is zero but its rotational energy can be increased

at the same place.

3 0

3 years ago

An archer puts a 0.30-kg arrow to the bowstring. An average force of 201 N is exerted to draw the string back 1.3 m. Assuming th

vovikov84 [41]

Answer:

41.74 m/s

Explanation:

The energy used to draw the bowstring = the kinetic energy of the arrow.

Fd = 1/2mv²................................ Equation 1

Where F = force, d = distance move string, m = mass of the arrow, v = speed of the arrow.

make v the subject of the equation

v = √(2Fd/m)...................... Equation 2

Given: F = 201 N, m = 0.3 kg, d = 1.3 m.

Substitute into equation 2

v = √(2×201×1.3/0.3)

v = √(1742)

v = 41.74 m/s.

Hence the arrow leave the bow with a speed of 41.74 m/s

3 0

3 years ago

Read 2 more answers

When a driver hits the brakes, his car decelerates from 50m/s at a uniform rate of 2.0m/s^2. His car stops after covering some d

Assoli18 [71]

Please find attached photograph for your answer. Please do comment whether it is useful or not.

7 0

3 years ago

A small fan has blades that have a radius of 0.0600 m. When the fan is turned on, the tips of the blades have a tangential accel

zhuklara [117]

Answer:

α = 395 rad/s²

Explanation:

Main features of uniformly accelerated circular motion

A body performs a uniformly accelerated circular motion when its trajectory is a circle and its angular acceleration is constant (α = cte). In it the velocity vector is tangent at each point to the trajectory and, in addition, its magnitude varies uniformly.

There is tangential acceleration (at) and is constant.

at = α*R Formula (1)

where

α is the angular acceleration

R is the radius of the circular path

There is normal or centripetal acceleration that determines the change in direction of the velocity vector.

Data

R = 0.0600 m :blade radius

at = 23.7 m/s² : tangential acceleration of the blades

Angular acceleration of the blades (α)

We replace data in the formula (1)

at = α*R

23.7 = α*(0.06)

α = (23.7) / (0.06)

α = 395 rad/s²

7 0

3 years ago

Jamison walks to a friends house. He walks 1000 meters north, then realizes he walked to far so he turns around and walks 200 me

olasank [31]

We will find that his average velocity is 1.11 m/s north-wise.

<h3>How to get the average velocity?</h3>

We define average velocity as the quotient between the displacement and the time it takes to make that displacement.

We know that he starts at the point 0m, where this measures distance in the north direction.

Then he moves 1000 meters north, so the new position is 1000m.

Then he moves 200 meters south, so the new position is:

1000m - 200m = 800m.

The displacement is equal to the difference between the final position (800m) and the initial position (0m).

D = 800m - 0m = 800m.

And we know that it takes 12 minutes to walk that distance. Because we want the average velocity in meters per second, we write:

12 minutes = 12*(60 seconds) = 720s

Then the average velocity is just:

AV = (800m)/(720s) = 1.11 m/s

And the direction of this average velocity is north-wise.

If you want to learn more about average velocity, you can read:

brainly.com/question/4931057

4 0

2 years ago