Conservation of Energy (answer in Netwons)

In summary, Pam, with a mass of 47.1 kg, is at rest on smooth, level, frictionless ice. She straps on a rocket pack which supplies a constant force for a distance of 15.3 m, causing Pam to acquire a speed of 59.2 m/s. The magnitude of the force required to achieve this velocity can be calculated using the equation F*x = 1/2 mv^2, where F is the force, x is the distance, m is the mass, and v is the final velocity. This results in an answer of 21,069.88 N. Additionally, the work energy theorem states that in the absence of any resistance force, the increase in total energy of a
  • #1
IBdoomed
16
0
Pam has a mass of 47.1 kg and she is at rest on
smooth, level, frictionless ice. Pam straps on
a rocket pack. The rocket supplies a constant
force for 15.3 m and Pam acquires a speed of
59.2 m/s.
What is the magnitude of the force?
Answer in units of N
The acceleration of gravity is 9.8 m/s^2

I know the KE= 1/2 mv^2 and that PE=mgh.
I do not know how to get an answer in Newtons however..
 
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  • #2
Do you know work energy theorem?
 
  • #3
You also need the equation for work done by a force acting over a distance.
 
  • #4
I do not! could you please explain?
 
  • #5
The theorem says in absence of any Resistance force increase in total energy of a body is equal to the work done on it. Here work is done by rocket pack force.
 
  • #6
and work= power/time right? so how do i solve this if i don't know how long she was moving?
 
  • #7
Power is not involved at all.
work = force*displacement
 
  • #8
oh sorry. well I'm pretty lost then... can you help me any more than this?
 
  • #9
work done = gain in PE + gain in KE
 
Last edited:
  • #10
I surrender.
 
  • #11
F*h = mgh + 1/2 mv^2 if it is going vertically
F*x = 1/2 mv^2 if it is moving horizontally
 

1. What is the law of conservation of energy?

The law of conservation of energy states that energy cannot be created or destroyed, but can only be transferred from one form to another. This means that the total amount of energy in a closed system remains constant over time.

2. How is energy conserved in everyday life?

Energy is conserved in everyday life through various processes such as photosynthesis, respiration, and combustion. For example, plants convert solar energy into chemical energy through photosynthesis, and animals use this stored energy for their own bodily functions. In addition, when fuel is burned, the chemical energy is converted into heat energy, which can be used to power machines or warm homes.

3. Can energy be converted from one form to another?

Yes, according to the law of conservation of energy, energy can be converted from one form to another. For example, electrical energy can be converted into mechanical energy in a blender, or chemical energy can be converted into thermal energy in a stove.

4. How is the conservation of energy related to the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, but can only be transferred from one form to another. This is directly related to the law of conservation of energy, as they both describe the principle that energy is conserved in a closed system.

5. What are some real-life applications of the law of conservation of energy?

The law of conservation of energy has many real-life applications, such as in the design of energy-efficient buildings, the development of renewable energy sources, and the understanding of natural processes like weather patterns and ecosystem dynamics. It is also used in industries such as transportation, manufacturing, and power generation to optimize energy usage and reduce waste.

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