- #1
hello478
- 165
- 14
- Homework Statement
- question c part ii) power produced by engine
- Relevant Equations
- p= f* v
How Do Power, Force, and Velocity Interact?
In summary, power, force, and velocity are interconnected concepts in physics that describe the relationship between energy and motion. Power is the rate at which work is done or energy is transferred, and it depends on both the force applied and the velocity of the object. Specifically, power can be calculated as the product of force and velocity when the force is acting in the direction of the motion. This relationship highlights how increasing either force or velocity can lead to greater power output, illustrating the dynamics of mechanical systems and the efficiency of energy use in various applications.
- #2
BvU
Science Advisor
Homework Helper
- 16,132
- 4,885
8628.46 ?
##\ ##
##\ ##
- #3
hello478
- 165
- 14
its by finding the component of weight along slopeBvU said:
- #4
BvU
Science Advisor
Homework Helper
- 16,132
- 4,885
So the slope is given, and so is the mass of the lorry. Given for you , that is.
But my telepathic capabilities are limited and I need a complete problem statement, typed out.
And: what are the directions of 8628.46 and the resistive force ?
##\ ##
But my telepathic capabilities are limited and I need a complete problem statement, typed out.
And: what are the directions of 8628.46 and the resistive force ?
##\ ##
- #5
hello478
- 165
- 14
i have attached the question image above..., is it not there? let me check againBvU said:
- #6
- 42,140
- 10,205
The F you need to use in P=Fv is the motive force delivered by the engine. This has to balance the opposing forces, the 5200N of resistance plus the gravitational component.hello478 said:
- #7
hello478
- 165
- 14
ok so in p=fvharuspex said:
the f would always be total force?
- #8
- 42,140
- 10,205
Depends what you mean by "total force". As you wrote, since the speed is constant the total force on the truck is zero.hello478 said:
- #9
hello478
- 165
- 14
yeah the net force would be zeroharuspex said:
but here... we would have to use the force which is causing the body to move(the total force, sum of resistive forces) with that velocity???
is this explanation fine?
- #10
- 42,140
- 10,205
Yes, that being the static frictional force on the tyres. We can consider that the motive force provided by the engine, though in reality what the engine provides is a torque.hello478 said:
Not sure what you mean by that. In the general case the truck is accelerating, so we have ##F_{net}=F_{static}+F_{resist}=ma##, ##F_{resist}## being negative. So the engine power would be ##F_{static}v=(ma-F_{resist})v##.hello478 said:
- #11
hello478
- 165
- 14
i meant that we would multiply the force which causes to move the lorry with the velocity it createsharuspex said:
also is this applicable to all cases?
- #12
- 42,140
- 10,205
You don't have to care what creates the velocity. What matters is that a force ##\vec F## is exerted at a point on a body while that point is moving with velocity ##\vec v##. The power transferred is ##\vec F\cdot\vec v##.hello478 said:
- #13
BvU
Science Advisor
Homework Helper
- 16,132
- 4,885
I'm still worried about the signs:
##\ ##
##\ ##
Last edited:
- #14
hello478
- 165
- 14
F would be 8628.46+5200
- #15
BvU
Science Advisor
Homework Helper
- 16,132
- 4,885
I agree
FAQ: How Do Power, Force, and Velocity Interact?
What is the relationship between power and force?
Power is the rate at which work is done or energy is transferred. When a force is applied to an object causing it to move, power can be calculated as the product of the force and the velocity at which the object moves in the direction of the force. Mathematically, Power (P) = Force (F) × Velocity (v).
How does velocity affect power?
Velocity directly affects power because power is the product of force and velocity. As velocity increases, for a constant force, the power also increases. Conversely, if velocity decreases, the power decreases, assuming the force remains constant.
Can power be generated without force?
No, power cannot be generated without force. Power is the rate of doing work, and work requires a force to be applied over a distance. Without force, no work is done, and consequently, no power is generated.
How do you calculate force if you know power and velocity?
If you know the power and velocity, you can calculate the force using the formula Force (F) = Power (P) / Velocity (v). This relationship shows that for a given power, if the velocity increases, the force decreases, and if the velocity decreases, the force increases.
What happens to power if both force and velocity are doubled?
If both force and velocity are doubled, the power increases by a factor of four. This is because power is the product of force and velocity. Mathematically, if the original power is P = F × v, then doubling both force and velocity gives the new power as P' = (2F) × (2v) = 4(F × v) = 4P.