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If you lift a box and then you start to walk at a constant velocity when are you working?
Wiki User
∙ 7y ago
It's a bit more of a vexed question if you are considering a human body rather than an inanimate object. To lift the box requires work. An object moving at constant velocity is not being worked upon. However, you are still performing work when you move your muscles.
Wiki User
∙ 7y ago
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A simple pendulum is hung in a stationary lift and its periodic time is T. what will be the effect on its periodic time T if the lift goes up with uniform velocity v?
Nothing (ignoring effects due to height). If the elevator is moving at a uniform velocity, relativity says the velocity doesn't matter.
What the apparent weight if the lift moves downward with constant speed?
If you are in a lift (elevator) moving at constant speed, whether up or down, and you have no visual contact with the outside, then you don't know that the lift is moving, and no physical experiment can detect the motion. Your apparent weight is the same as when you're at 'rest'.
How does the direction of the lift on a plane compare with its weight as it flies at a constant speed and altitude?
lift acts upward, and weight acts downward
What forces act on a plane sitting still on the tarmac?
It has weight-- but not lift. It also has no thrust nor drag. It needs forward movement/trust, velocity, and lift to get off the ground.
What two factors determine the amount of lift achieved by an airplane?
velocity and the difference in pressure above and below the wings
Are you doing work lifting something?
Yes, you are working against the force of gravity when you lift something. The amount of work you do depends on the height you lift it by, h, and the mass of the object, m. work = mgh, where g is the gravitational constant.
How do airplanes stay steady?
There are four forces act on an aircraft in flight: lift, weight, thrust, and drag. From Newton's first law of motion, if there is no net external force, the object will maintain constant velocity. i.e lift=wait , thrust=drag. This condition is called "cruise". In this situation, airplane can stay steady (constant velocity). But the weight of the aircraft is decrease a little due to fuel burned per time. If forces become unbalanced, aircraft will move by Newton's second law of motion.
When working out your shoulders is it bad to lift heavy weights?
Best to start out with a weight you can lift for 10-12 reps. As you progress you can lower the reps to what feels most comfortable. Everyone is different, and some can start heavier, but 10-12 reps is a good place to start.
How old do you have to be to join work out world?
The perfect age to build muscle is 18, but you can start working out at 16, though it is not recommended that you lift heavy weights or weights you're forcing your body to lift.
How lift produced in aircraft?
lift = 1/2 air density x velocity squared x surface area
A simple pendulum is hung in a stationary lift and its periodic time is T. what will be the effect on its periodic time T if the lift goes up with uniform velocity v?
Nothing (ignoring effects due to height). If the elevator is moving at a uniform velocity, relativity says the velocity doesn't matter.
What is the relation between lift force and mach number in supersonic speed?
The only relationship is that the greater the velocity of Air over a Lifting Body (Wing in general), the greater the LIFT. HOWEVER, you cannot say that the reverse is true...that is, the greater the LIFT the higher the Velocity. You can change Lift by changing the Wing DESIGN. When Landing an Airliner deploys its WING FLAPS to create greater Lift at lower velocities.
What does lift and stag mean in a rocket?
LIft = coefficient times density times velocity squared times wing area divided by 2 drag= coefficient times density times velocity squared over 2 times reference area
What the apparent weight if the lift moves downward with constant speed?
If you are in a lift (elevator) moving at constant speed, whether up or down, and you have no visual contact with the outside, then you don't know that the lift is moving, and no physical experiment can detect the motion. Your apparent weight is the same as when you're at 'rest'.
How does the direction the of the lift on a plane compare with its weight as it flies at a constant speed and altitude?
lift acts upward, and weight acts downward
How does the direction of the lift on a plane compare with its weight as it flies at a constant speed and altitude?
lift acts upward, and weight acts downward
Do you need a spotter when your working on a scissor lift?
when is a spotter required when operating scissor lift equipment
