How much time does it take to roll a ball 2 meters on a steep slope

12. One object has half the mass of another object. The first object also has half the ---.

Tanya [424]

The first object also has half the inertia.

Answer: Option A

Explanation:

Inertia is the tendency of an object to remain in its state. It resists the change in the state of object due to any external forces. So the inertia is the property of an object to resists the change in its state due to any kind of external force. Thus as the mass decreases, the central mass of inertia of the object will also decrease as both are directly proportional to each other.

3 0

3 years ago

A 30 kg child sitting 5.0 m from the center of a merry-go-round has a constant speed of 5.0 m/s. while she remains seated in the

expeople1 [14]

Let us say that v is the tangential velocity of the object, a to be the centripetal (which acts towards the center of the circle) acceleration and F as the centripetal force, r to be the radius of the circle and m is mass of the child. 

a = v^2 / r

F = ma = mv^2/r

Applying the given values to the equation:

F=30*(5^2/5) => 30*(25/5) => 30*5 => 150 Newtons

Now work is Force times distance, the distance is simply the circumference of the circle.

d = C = 2 * pi * r = 2 * pi * 5 = 10π m

W = F * d = 150 N * 10π m

W = 1500π J = 4712.39 J

8 0

3 years ago

A ray is incident on a film of thickness t and the index of refraction n=1.6 at an angle θ = 35 degrees. Find the angle of refra

lidiya [134]

Answer

Given,

refractive index of film, n = 1.6

refractive index of air, n' = 1

angle of incidence, i = 35°

angle of refraction, r = ?

Using Snell's law

n' sin i = n sin r

1 x sin 35° = 1.6 x sin r

r = 21°

Angle of refraction is equal to 21°.

Now,

distance at which refractive angle comes out

d = 2.5 mm

α be the angle with horizontal surface and incident ray.

α = 90°-21° = 69°

t be the thickness of the film.

So,

$tan \alpha = \dfrac{t}{d/2}$

$tan 61^0 = \dfrac{t}{2.5/2}$

t = 2.26 mm

Hence, the thickness of the film is equal to 2.26 mm.

4 0

3 years ago

What amount of energy is required to change a spherical drop of water with a diameter of 1.60 mm 1.60 mm to six smaller spherica

Vikki [24]

Answer:

0.4731 μJ

Explanation:

Surface tension = surface energy/surface area.

Let the radius of the big sphere be R = 0.8 mm = 8 × 10⁻⁴ m

Radius of the small spheres = r

Surface Area of the big sphere = 4πR² = 4π(8 × 10⁻⁴)² = 0.0000080425 m² = 8.0425 × 10⁻⁶ m²

Surface energy of the big sphere = surface tension × surface area = 72 × 10⁻³ × 8.0425 × 10⁻⁶ = 5.791 × 10⁻⁷ J

Volume of big sphere = 4πR³/3 = 4π(8.0 × 10⁻⁴)³/3 = 2.145 × 10⁻⁹ m³

This volume is separated into 6 equal smaller drops,

Volume of one small sphere = (2.145 × 10⁻⁹)/6 = 3.574 × 10⁻¹⁰ m³

Each small sphere would have a radius as calculated from

4πr³/3 = 3.574 × 10⁻¹⁰ = 0.00044 m = 0.44 mm

Surface area of each small sphere = 4πr² = 4π(0.00044)² = 0.0000024356 m² = 2.436 × 10⁻⁶ m²

Surface area of 6 small spheres = 6 × 2.436 × 10⁻⁶ = 0.0000146141 m²

Surface energy of 6 small spheres = surface tension of water × Surface area of 6 small spheres = 72 × 0.001 × 0.0000146141 = 0.0000010522 J = 1.0522 × 10⁻⁶ J

Difference in surface energy of the big sphere and 6 small spheres = (1.0522 × 10⁻⁶) - (5.791 × 10⁻⁷) = 0.0000004731 J = 4.731 × 10⁻⁷ J = 0.4731 μJ

7 0

3 years ago

a waterwheel built in Hamah, Syria, has a radius of 20 m . If the tangential velocity at the wheels edge is 7.85 m/s , what is t

gtnhenbr [62]

Answer:

3.08m/s²

Explanation:

Given parameters:

Radius = 20m

Tangential velocity = 7.85m/s

Unknown:

Centripetal acceleration = ?

Solution:

Centripetal acceleration is the acceleration of a body along a circular path.

it is mathematically given as;

a = $\frac{v^{2} }{r}$

v is the tangential velocity

r is the radius

a = $\frac{7.85^{2} }{20}$ = 3.08m/s²

4 0

3 years ago