How far is it between the cafeteria and the swimming pool

A moving billiard ball hits another ball at rest, causing the first ball to stop moving as the second rolls away. If the two bal

mario62 [17]

<span>The momentum of the second ball will depend on the acceleration of the first moving ball.</span>

3 0

3 years ago

Read 2 more answers

The number of revolutions of two pulleys is inversely proportional to their diameters. If a 24-inch diameter pulley making 400 r

Fed [463]

Answer:

C) 1200 rpm

Explanation:

$D_1$ = Diameter of bigger pulley = 24 inch

$D_2$ = Diameter of smaller pulley = 8 inch

$N_1$ = Speed of bigger pulley = 400 rpm

$N_2$ = Speed of smaller pulley

The relation between revolutions per minute and diameter is that they are inversely proportional.

$\frac{N_1}{N_2}=\frac{D_2}{D_1}\\\Rightarrow \frac{400}{N_2}=\frac{8}{24}\\\Rightarrow N_2=\frac{24\times 400}{8}\\\Rightarrow N_2=1200\ rpm$

The number of revolutions per minute of the smaller pulley is 1200 rpm

7 0

3 years ago

Group one on the periodic table shares which characteristics.?

Dmitry_Shevchenko [17]

Group one on the periodic table, also known as the alkali metals, all:
- form ions with a charge of +1
- display similar extreme chemical behaviour
- have typical metallic properties
- are far too reactive to be found naturally in their pure forms

4 0

3 years ago

A disk between vertebrae in the spine is subjected to a shearing force of 425 N. Find its shear deformation, taking it to have a

zzz [600]

Answer:

option A

Explanation:

given,

shear force = 425 N

Shear modulus = 1.7 × 10⁹ N/m²

disk equivalent to solid cylinder

height = 0.7 cm and diameter = 6.50 cm

$\delta = \dfrac{VL}{AG}\\\\\delta = \dfrac{425\times 0.007}{0.25 \times \pi d^2\times 1.7\times 10^9}\\\\\delta = \dfrac{425\times 0.007}{0.25 \times \pi\times 0.065^2\times 1.7\times 10^9}\\\\\delta = 5.27 \times 10^{-7} m$

hence, the correct answer is option A

3 0

4 years ago

To measure the coefficient of kinetic friction by sliding a block down an inclined plane the block must be in equilibrium.

lozanna [386]

Answer:

a)

Explanation:

A block sliding down an inclined plane, is subject to two external forces along the slide.
One is the component of gravity (the weight) parallel to the incline.
If the inclined plane makes an angle θ with the horizontal, this component (projection of the downward gravity along the incline, can be written as follows:

$F_{gp} = m*g* sin \theta (1)$

(taking as positive the direction of the movement of the block)

The other force, is the friction force, that adopts any value needed to meet the Newton's 2nd Law.
When θ is so large, than the block moves downward along the incline, the friction force can be expressed as follows:

$F_{f} = \mu_{k} * N (2)$

The normal force, adopts the value needed to prevent any vertical movement through the surface of the incline:

$N = m*g* cos \theta (3)$

In equilibrium, both forces, as defined in (1), (2) and (3) must be equal in magnitude, as follows:

$m*g* sin \theta = \mu_{k} * m*g* cos \theta$

As the block is moving, if the net force is 0, according to Newton's 2nd Law, the block must be moving at constant speed.
In this condition, the friction coefficient is the kinetic one (μk), which can be calculated as follows:

$\mu_{k} = tg \theta$

8 0

3 years ago