The diagram below shows waves A and B in the same medium

An 80.0 kg skier slides down a hill shaped as shown. Assume

umka21 [38]

The height above the ground from where the skier start is 11.5 m.

<h3>Conservation of energy</h3>

The height above the ground from where the skier start is determined by applying the principle of conservation of energy as shown below;

P.E = K.E

mgh = ¹/₂mv²

gh = ¹/₂v²

$h = \frac{v^2}{2g} \\\\h = \frac{15^2}{2 \times 9.8} \\\\h = 11.5 \ m$

Thus, the height above the ground from where the skier start is 11.5 m.

Learn more about conservation of energy here: brainly.com/question/166559

8 0

3 years ago

A student stretches a spring, attaches a 1.20 kg mass to it, and releases the mass from rest on a frictionless surface. The resu

Sphinxa [80]

Answer:

the speed of the mass when it is halfway to the equilibrium position is 1.26 m/s

Explanation:

Given that;

mass of the object m = 1.20 kg

period of oscillation = 0.750 s

Amplitude ( A/x) = 15.0 cm = 0.15 m

now;

a) Determine the oscillation frequency;

oscillation frequency f = 1/T

we substitute

f = 1 / 0.750 s

f = 1.33 Hz

Therefore, the oscillation frequency is 1.33 Hz

b) Determine the spring constant;

we solve for spring constant from the following expression;

T = 2π√(m/k)

k = 4π²m / T²

so we substitute

k = (4π² × 1.20) / (0.750)²

k = 47.3741 / 0.5625

k = 84.22 N/m

Therefore, the spring constant is 84.22 N/m

c) determine the speed of the mass when it is halfway to the equilibrium position

So, at equilibrium, the energy is equal to K.E

such that;

1/2mv² = 1/2kx²

mv² = kx²

v² = kx² / m

v = √( kx²/m)

we substitute

v = √( 84.22×(0.15 m)²/ 1.2 )

v = √( 1.89495 / 1.2 )

v = √ 1.579125

v = 1.26 m/s

Therefore, the speed of the mass when it is halfway to the equilibrium position is 1.26 m/s

3 0

3 years ago

A 5kg object is moving downward at a speed of 12m/s. If it is currently 2.6m above the ground, what is its potential energy? Use

motikmotik

Don’t trust the people that give you these file things to click on it’s a scam!

4 0

3 years ago

A car changes chemical energy from fuel into thermal energy and ________ energy.

Shkiper50 [21]

Answer:

Mechanical energy

Explanation:

A car changes chemical energy from fuel into thermal energy and mechanical energy.

Mechanical energy can be defined as the type of energy that is possessed by an object due to its motion or position. Mechanical energy is the sum of potential energy and kinetic energy, that is, the sum of energy in motion and stored energy. Examples of mechanical energy includes driving a car, riding a bicycle, listening to music etc.

Types of mechanical energy

1. Motion energy (kinetic energy)

2. Stored energy(potential energy)

Mechanical energy = Kinetic energy + Potential energy

4 0

3 years ago

A liquid in a test tube has a curved surface such that the edges touching the glass are higher than the surface at the center. T

Temka [501]

Answer:

False

Explanation:

The cohesive forces of the liquid are greater than the adhesive forces hence the liquid is drawn inwards instead of spreading out. cohesion refers to the force of attraction between molecules of the same kind. it keeps molecules of the same kind together. It prevents the liquid from spreading out and wetting the glass hence the liquid will have a curved surface when in contact with the glass and this curved surface will be higher than the surface at the center. When the adhesive forces are greater, the curved surface will be lower than the surface at the center.

3 0

3 years ago