Which of the following statements about psychodynamic perspective is not true?

Sam stands on a 20 m high cliff and throws a 45 g rock with an initial velocity of 5 m/s [forward] to the water below. Use the c

storchak [24]

Answer:

v = 12.52 [m/s]

Explanation:

To solve this problem we must use the energy conservation theorem. Which tells us that potential energy is transformed into kinetic energy or vice versa. This is more clearly as the potential energy decreases the kinetic energy increases.

Ep = Ek

where:

Ep = potential energy [J] (units of joules]

Ek = kinetic energy [J]

Ep = m*g*h

where:

m = mass of the rock = 45 [g] = 0.045 [kg]

g = gravity acceleration = 9.81 [m/s²]

h = elevation = (20 - 12) = 8 [m]

Ek = 0.5*m*v²

where:

v = velocity [m/s]

The reference level of potential energy is taken as the ground level, at this level the potential energy is zero, i.e. all potential energy has been transformed into kinetic energy. In such a way that when the Rock has fallen 12 [m] it is located 8 [m] from the ground level.

m*g*h = 0.5*m*v²

v² = (g*h)/0.5

v = √(9.81*8)/0.5

v = 12.52 [m/s]

5 0

3 years ago

A space rover weighs less on Mars than it does on Earth. Which statement explains this difference? A. The gravitational constant

Maksim231197 [3]

Answer:

B. The mass of Mars is less than the mass of Earth.

Explanation:

Mass of an object is the constant anywhere in the universe.

The weight of an object is equal to the gravitational force acting on it.

Weight is given by

$W=\dfrac{GMm}{R^2}\\\Rightarrow W=\dfrac{GM}{R^2}m\\\Rightarrow W=mg$

where

G = Gravitational constant

M = Mass of Planet

R = Radius of planet

m = Mass of object

g = Acceleration due to gravity

So weight of an object depends on the acceleration due to gravity on that planet. The acceleration due to gravity depends on the mass and radius of the planet.

The weight of the object is less on Mars because mars has less mass compared to Earth.

6 0

3 years ago

Observer A, who is at rest in the laboratory, is studying a particle that is moving through the laboratory at a speed of v=0.8c

Studentka2010 [4]

Answer:

30.96 m

Explanation:

If the particle has a lifetime of 129 ns as measured by observer A, and has a speed of 0.8c as measured by observer A, the distance between the markers will be:

d = v * Δt

v = 0.8*c = 0.8 * 3e8 = 2.4e8

Δt = ζ = 129 ns = 1.29e-7 s

d = 2.4e8 * 1.29e-7 = 30.96 m

This is the distance as measured by observer A.

3 0

3 years ago

Caroline conducts research on how the amount of fiber in a student's breakfast affects their grades in school. How should she re

Evgesh-ka [11]

Answer:

data table and line graph ( first choice)

8 0