How many galaxies do astronomers estimate are in the universe.

Suppose you throw a baseball downward from a roof so that it initially has 120 J of gravitational potential energy, and 10 J of

Volgvan

Answer:

B.

It will be greater than 10 J.

Explanation:

The total mechanical energy of an object is the sum of its potential energy (PE) and its kinetic energy (KE):

E = PE + KE

According to the law of conservation of energy, when there are no frictional forces on an object, its mechanical energy is conserved.

The potential energy PE is the energy due to the position of the object: the highest the object above the ground, the highest its PE.

The kinetic energy KE is the energy due to the motion of the object: the highest its speed, the largest its KE.

Here at the beginning, when it is at the top of the roof, the baseball has:

PE = 120 J

KE = 10 J

So the total energy is

E = 120 + 10 = 130 J

As the ball falls down, its potential energy decreases, since its height decreases; as a result, since the total energy must remain constant, its kinetic energy increases (as its speed increases).

Therefore, when the ball reaches the ground, its kinetic energy must be greater than 10 J.

7 0

4 years ago

Read 2 more answers

The action of property being taken directly from a person or in that person's presence must be an element in which type of crime

grin007 [14]

B, larceny because that's theft of personal property.

5 0

3 years ago

Please help :/ The same motor is used in rockets with different masses. The rockets have different accelerations. According to N

Ymorist [56]

Answer:

1. As rocket mass increases, acceleration decreases.

2. The inverse of the mass of the boat.

Explanation:

1. Newton's second law of motion states;

F = ma

where F is the force applied, m is the mass and a is the acceleration.

Therefore, increasing the mass of a rocket increases its weight which would reduce its acceleration provided that the force is constant. Thus, as rocket mass increases, acceleration decreases.

2. The slope of the graph can be expressed as;

From Newton's second law,

F = ma

Slope = (Δa) ÷ (ΔF)

Slope = $\frac{a}{F}$