Conservation of Energy (answer in Netwons)

AI Thread Summary
Pam, with a mass of 47.1 kg, accelerates to a speed of 59.2 m/s on frictionless ice after using a rocket pack over a distance of 15.3 m. The discussion revolves around calculating the force exerted by the rocket pack using the work-energy theorem. The relevant equations include the work done by the force, which is equal to the change in kinetic energy, represented as F*x = 1/2 mv^2. Participants clarify that the power and time are not necessary for this calculation, focusing instead on the relationship between work, force, and displacement. The conversation emphasizes understanding the application of these physics principles to solve for the force in Newtons.
IBdoomed
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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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Do you know work energy theorem?
 
You also need the equation for work done by a force acting over a distance.
 
I do not! could you please explain?
 
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.
 
and work= power/time right? so how do i solve this if i don't know how long she was moving?
 
Power is not involved at all.
work = force*displacement
 
oh sorry. well I'm pretty lost then... can you help me any more than this?
 
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
 

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