All categories

3 years ago

The amount of heat needed

1 answer:

4 0

J=joules, c=specific heat, q= energy, and the Tf and Ti are the final and initial temperatures cause I couldn't find a delta sign.

$Q=mc(T_{f}-T_{I}) \\ 33000j=2kg*c*80 \\\frac{33000j}{2kg*80} =c \\ c=206.25jkg^{-1}$

You might be interested in

A ball is launched with initial speed v from ground level up a frictionless slope (This means the ball slides up the slope witho

amid [387]

Answer:

hmax = 1/2 · v²/g

Explanation:

Hi there!

Due to the conservation of energy and since there is no dissipative force (like friction) all the kinetic energy (KE) of the ball has to be converted into gravitational potential energy (PE) when the ball comes to stop.

KE = PE

Where KE is the initial kinetic energy and PE is the final potential energy.

The kinetic energy of the ball is calculated as follows:

KE = 1/2 · m · v²

Where:

m = mass of the ball

v = velocity.

The potential energy is calculated as follows:

PE = m · g · h

Where:

m = mass of the ball.

g = acceleration due to gravity (known value: 9.81 m/s²).

h = height.

At the maximum height, the potential energy is equal to the initial kinetic energy because the energy is conserved, i.e, all the kinetic energy was converted into potential energy (there was no energy dissipation as heat because there was no friction). Then:

PE = KE

m · g · hmax = 1/2 · m · v²

Solving for hmax:

hmax = 1/2 · v² / g

4 0

4 years ago

You and a highway patrolman are driving at constant speeds in opposite directions on a straight highway. The patrolman is drivin

kompoz [17]

Answer: 75 mph

Explanation:

The Relative Speed for a mobile is equal to the diference between the object and the observer:

Relative Speed (Rs) = Object's Velocity - Observer's Velocity

Thinking on those terms, we would need to have a universal observer to do any understandable measurement on daily basics. This is why we all use earth as a Static Observer for every measurement we do everyday.

Using Earth as an observer, the Velocity for the Patrolman is:

Patrolman Velocity (Vp) = 60 mph

Because the radar gun does measure the Relative Speed for the object, which is 135 mph, we need to work with the equation to find the Velocity using Earth as a reference.

Object's Relative Velocity = Object's Velocity - Patrolman's Velocity

Object's Velocity = Object's Relative Velocity + Patrolman's Velocity

We need to keep in mind, the Patrolman is going on the opposite direction. Because of this the sign for his velocity should be negative.

Object's Velocity = 135 mph + ( -60 mph)

Object's Velocity = 135 mph - 60 mph

Object's Velocity = 75 mph

3 0

3 years ago

5. Dry ice is an example of _________, which is the process of a solid turning directly into a gas. (1 point) precipitation melt

ki77a [65]

5. Dry ice is an example of _________, which is the process of a solid turning directly into a gas. (1 point)

sublimation

6. The ____ is a unit of force. (1 point)

newton

7. Which of the following is the boiling point of water? (1 point)

100°C

8. Which of the following describes the molecular structure of water at 40°C? (1 point)

water molecules are close together and moving freely around each other

6 0

3 years ago

Which system of government has a leader that takes power by force

kvv77 [185]

Answer:

The Autocratic system of governance

Explanation:

This is because,in Autocratic system of governance decision making is done by only individual. And his/her decision is final.

5 0

3 years ago

Read 2 more answers

How is a reference point defined?

nevsk [136]

Simply be used as a reference point to describe its position. a fact forming the basis of an evaluation or assessment; criterion. They had few cultural reference points in common.

6 0

3 years ago