1. Two students have volunteered to explore the galaxy in a

A diver shines an underwater searchlight at the surface of a pond (n = 1.33). At what angle (relative to the surface) will the l

allsm [11]

Answer:

41.2°

Explanation:

Total internal reflection is the reflection of the incident ray at the interface between two media in which one of the media has a lower refractive index than the other. It occurs when the angle of incidence in the denser medium exceeds the critical angle.

The critical angle is the angle of incidence in the denser medium when the angle of incidence in the less dense medium is 90°.

Since

n= 1/sin C

C= sin^-(1/n)

C= sin^-(1/1.33)

C= 48.8°

Hence angle of incidence= 90-48.8 = 41.2°

4 0

3 years ago

A 25kg chair initially at rest on a horizontal floor requires 165 N force to set it in motion. Once the chair is in motion, a 12

bazaltina [42]

The coefficient of static friction between the chair and the floor is 0.67

Explanation:

Given:

Weight of the chair = 25kg

Force = 165 N (F_applied)

Force = 127 N (F_max)

To find: Coefficient of static friction

The “coefficient of static friction” between a chair and the floor is defined as the ration of maximum force to the normal force acting on the chair

μ_s= $F_{max}/F_{n}$

The F_n is equal to the weight multiplied by its gravity

∴ $F_{n}$ =mg

Thus the coefficient of static friction changes as

μ_s= $F_{max}/mg$

μ_{s} = $=165N/((25kg)\times(9.80 m/s^2 ) )$

= 0.67

3 0

3 years ago

A line of dominos is knocked down. Which explanation is true?

Llana [10]

B: an increase in acceleration caused an increase in force.

This is based on the concept of force on an object.

Now, formula for force is commonly known as;

Force = mass × acceleration

Now, mass and acceleration are the input values that make the output which is the Force to either increase or decrease.

Now, for the line of dominoes to fall, it means that the force was so overwhelming that the dominoes couldn't resist it.

Now, this output which is the force became so much as a result of the increase in acceleration of the motion that triggered its movement.

Moreover, the force is directly proportional to the acceleration!

Thus, we can say that an increase in acceleration caused an increase in force.

Read more at; brainly.in/question/25954363

4 0

3 years ago

Read 2 more answers

In which of these samples do the molecules most likely have the most kinetic energy? (2 points)

Vinvika [58]

D, water vapor. Gaseous state would have more kinetic energy, they are moving faster. If you have to compare the same state, then higher temperature would have the higher kinetic energy. But if you have solid and liquid at the same temperature - then liquid would have more.

4 0

3 years ago

A 500 W immersion heater is placed in a pot containing 1.00 L of water at 20oC. (a) How long will the water take to rise to the

tatiyna

Answer:

96 s.

Explanation:

(a)

From the question,

Q = cm(t₂-t₁)................... Equation 1

Where Q = heat required to boil the water, c = specific heat capacity of the water, m = mass of the water, t₂ = final temperature of water, t₁ = initial temperature of water

Note: The boiling point of water = 100 °C

Given: c = 4200 J/kg.°C, t₂ = 100 °C, t₁ = 20 °C

mass of water = density×volume

m = D×v, Where D = 1000 kg/m³, v = 1.00 L = 0.001 m³

Hence, m = 1000×0.001 = 1 kg.

Substitute into equation 1

Q = 4200×1(100-20)

Q = 4200×8

Q = 33600 J.

But,

P = Q/t................... Equation 2

make t the subject of the equation

t = Q/P................. Equation 3

Where P = power, t = time

From the question,

70 % of the available energy is absorbed by water.

P = 0.7×500 = 350 W.

Substitute into equation 2

t = 33600/350

t = 96 s.

6 0

3 years ago