Ask question

Ask question

All categories

3 years ago

9

A 2.10 kg textbook rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter

is 0.170 m, to a hanging book with mass 3.00 kg. The system is released from rest, and the books are observed to move 1.20 m in 0.900 s.(a) What is the tension in each part of the cord? (b) What is the moment of inertia of the pulley about its rotation axis?

1 answer:

AVprozaik [17]3 years ago

4 0

Answer:

Explanation:

Answer:

Explanation:

mass of book, m = 2.10 kg

diameter of pulley, = 0.170 m

radius of pulley, R = 0.085 m

mass of hanging book, m' = 3 kg

initial velocity, u = 0 m/s

distance, s = 1.2 m

time, t = 0.9 s

Let a be the acceleration of the system and T and T' is the tension in the string which is horizontal and vertical respectively.

Use second equation of motion

s = ut + 0.5 at²

1.2 = 0 + 0.5 x a x 0.9 x 0.9

a = 2.96 m/s²

(a) Use second equation of motion

T = ma

T = 2.10 x 2.96

T = 6.216 N

m'g - T' = m'a

3 x 9.8 - T' = 3 x 2.96

T' = 20.52 N

(b) Let the moment of inertia of the pulley is I.

So, (T' - T)R = I x α

(20.52 - 6.216) x 0.085 = I x 2.96 / 0.085

I = 0.035 Kgm²

You might be interested in

Pulsars are neutron stars that emit X rays and other radiation in such a way that we on Earth receive pulses of radiation from t

stira [4]

Answer:

(a) $a_{c} = 5.41\times 10^{9} m/s^{2}$

(b) $a_{t} = 2.99\times 10^{- 5} m/s^{2}$

Given:

Time period of Pulsar, $T_{P} = 33.085 ms == 33.085\times 10^{- 3} s$

Equatorial radius, R = 15 Km = 15000 m

Spinning time, $t_{s} = 9.50\times 10^{10}$

Solution:

(a) To calculate the value of the centripetal acceleration, $a_{c}$ on the surface of the equator, the force acting is given by the centripetal force:

$m\times a_{c} = \frac{mv_{c}^{2}}{R}$

$a_{c} = \frac{v_{c}^{2}}{R}$ (1)

where

$v_{c} = \frac{distance covered(i.e., circumference)}{ T}$

$v_{c} = \frac{2\pi R}{Time period, T}$ (2)

Now, from (1) and (2):

$a_{c} = R\frac({2\pi )^{2}}{T^{2}}$

$a_{c} = 15000\frac{2\pi )^{2}}{(33.085\times 10^{- 3})^{2}}$

$a_{c} = 5.41\times 10^{9} m/s^{2}$

(b) To calculate the tangential acceleration of the object :

The tangential acceleration of the object will remain constant and is given by the equation of motion as:

$v = u + a_{t}t_{s} = 0$

where

u = $v_{c}$

$a_{t} = - \frac{2\pi R}{Tt_{s}}$

$a_{t} = - \frac{2\pi 15000}{33.085\times 10^{- 3}\times 9.50\times 10^{10}}$

$a_{t} = 2.99\times 10^{- 5} m/s^{2}$

7 0

3 years ago

A cork floats on the surface of an incompressible liquid in a container exposed to atmospheric pressure. The container is then s

yaroslaw [1]

Question:

A cork floats on the surface of an incompressible liquid in a container exposed to atmospheric pressure. The container is then sealed and the air above the liquid is evacuated. The cork:

A. sinks slightly

B. rises slightly

C. floats at the same height

D. bobs up and down about its old position

Answer:

The correct answer is C) floats at the same height

Explanation:

The liquid is incompressible because its density very high and leaves no room for further compaction whether or not there is atmospheric pressure. So when you put a cork on the liquid, pressure or no pressure, there is no displacement hence it floats on the same height regardless of the absence of air.

Cheers!

6 0

3 years ago

A difference in electric potential is commonly known as voltage, and is provided by standard batteries. If you built two identic

Lapatulllka [165]

Answer:

higher

Explanation:

A bigger voltage will result in a faster movement of charge.

8 0

4 years ago

To develop a product that warms peoples hands would you use an exothermic or endothermic reaction? Why?

il63 [147K]

Exothermic because exothermic reactions transfer energy to the surroundings. Endothermic reactions take in energy from the surroundings, so if you want to warms people's hands you should use exothermic chemical reaction for the product.

4 0

3 years ago

Read 2 more answers

Competitive divers pull their limbs in and curl up their bodies when they do somersaults. Just before entering the water, they f

Akimi4 [234]

Answer:

The angular velocity is reduced when the body is fully stretched.

Explanation:

Divers keep there bodies as compact as possible just to increase the angular velocity.

When they extend their limbs to enter straight down the angular momentum helps them to dive. The angular velocity is reduced when the body is fully stretched and diver's inertia is also not reduced. Thus a streamlined shape is formed which helps to penetrate more deeper into the water.

The impact area is reduced when fully stretched body is entered in to the water.

3 0

3 years ago