N-Gin said:Just look for the forces acting on the fish. You know it's acceleration and scale reading is actually the force between the fish and the scale (spring).
You can also solve this by using fictitious force (elevator is non-inertial reference frame).
N-Gin said:Gravity pulls the fish down, and the spring pulls it up. Force from the spring is greater, so the fish (along with the elevator and everything inside) accelerates upwards. So, you have
[tex]m\vec{a}=m\vec{g}+\vec{F},[/tex]
where [itex]\vec{F}[/itex] is elastic force of the spring. When you get rid of the vectors, you have
[tex]ma=-mg+F.[/tex]
I assumed that upwards is the positive direction. Everything else (that points downwards) is negative - gravity in this case.
Ogakor said:Homework Statement
A proud angler hangs her catch from a spring balance, which is supported from the roof of an elevator.
a.) if the elevator has an upward acceleration of 2.45m/s2 and the balance reads 50.0N, what is the true weight of the fish?
b.) Under what circumstances will the balance read 30.0N?
c.) What will the balance read if the cable breaks?
given:
a = 2.45m/s2
g = 9.8 m/s2
wbalance = 50.0N
wtrue = ?
what formulas will I use? Please help
Both. A weight is a force. While the elevator is going upward, the net force on the spring (so the reading on the scale) is the weight of the fish, mg, plus the "ma" where m is the mass of the fish (not weight, weight is mg) and a is the acceleration of the elevator.Ogakor said:Im so confused... is the 50.0N a weight or a force?
Newton's laws of motion are a set of three physical laws that describe the relationship between an object's motion and the forces acting upon it. They were developed by Sir Isaac Newton in the late 17th century and are considered fundamental principles in the field of classical mechanics.
The first law of motion, also known as the law of inertia, states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. This means that an object will not change its state of motion unless a force is applied to it.
The second law of motion, also known as the law of acceleration, states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This means that the larger the force acting on an object, the greater its acceleration will be, and the more massive the object, the smaller its acceleration will be.
The third law of motion, also known as the law of action and reaction, states that for every action, there is an equal and opposite reaction. This means that when a force is applied to an object, the object will exert an equal and opposite force back on the object applying the force.
Newton's laws of motion have many practical applications in everyday life. For example, the first law explains why objects remain at rest or in motion unless acted upon by a force, which can be seen in activities such as driving a car or playing sports. The second law helps us understand how much force is needed to move an object, such as pushing a shopping cart or riding a bike. The third law can be observed when jumping on a trampoline or rowing a boat, where the force of the action creates an equal and opposite reaction.