Need Help With Physics Question In Hw

I NEED HELP WITH PHYSICS HW!!!!?

Hey Hey Hey!!!!

a) Im guessing by true weight you mean the weight of the fish when only gravity is acting on it.

Any ways your told the Net force F(up)=70.0N (it is up because it is the reaction force that gives the fish the apparent weight)
Now you need to find the actual weight of the fish, W=mg, substituting m for the mass of the fish so:

F(weight)=(9.8)(m) <---- 9.8 is acceleration of gravity

And finally we need the net force which is causing the fish to move upwards, which is the mass of the fish multiplied by the acceleration of the lift.
ΣF=(2.45)(m)

Now we can substitute these values into the equation
ΣF = F(up) + F(weight)
ΣF = F(up) - F(weight) <----- taking into account that up is +ive
2.45m + 9.8m = 70
and so we get m = 5.71kg
to get the weight just multiply by g

b) so now we want F(normal) = 38N

F(weight)=(-9.8)(5.71) the weight is negative as the acceleration is going down
and ΣF=a(5.71) <----- we need to find a (if a is -ive then the lift is going down and if +ive its going up, even though it might be obvious which way it would it would need to be going)

ΣF = F(noraml) + F(weight) <--- no need to manipulate signs as we have already taken care of that when finding each component.

a(5.71) = 38 + (-9.8)(5.71)
a = -3.15m/s^2
the value of a is negative so the lift needs to be accelerating down at 3.15m/s^2 for the weight to be 38N

c) If the cable snapped the lift would be in free fall and would be accelerating at 9.8m/s^2 so the normal force would be 0N and as apparent weight is given by the normal force the scale would read 0N

:D hope that helped

Need help with Physics Hw!?

(2)   Time = Energy ⁄ Power

If you double engine power it will take half the time to achieve the same final speed
or the same final energy.

  Answer: 5 seconds

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...

(3) No need to use the actual numbers given.
  Only the ratio of initial speeds = (120 Km/h) ⁄ (60 Km/h) = 2
  is needed.

Here the acceleration (or deceleration in this problem) is constant:
 a = constant in (m/sec²) and "a" is a negative value implying deceleration.
The actual value of "a" however is irrelevant for this problem.

       (Vғ)² – (Vi)² = 2 • a • D ... final speed = Vғ = 0

             D = -  (Vi)² ⁄ (2a) ... skidding distance = D

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...

Case w: Viw = 60 Km/h  Dw = 20 m

        Dw = -  (Viw)² ⁄ (2a)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...

Case ƶ: Viƶ = 120 Km/h  Dƶ = ?

   Dƶ = -  (Viƶ)² ⁄ (2a) ... substitute: Viƶ = 2 •  (Viw) ... speed is doubled

   Dƶ = -  (2  •  Viw)² ⁄ (2a)

   Dƶ = -  4  •  (Viw)² ⁄ (2a) ... recall: Dw = -  (Viw)² ⁄ (2a)

   Dƶ = 4  •  (Dw)

... so the skidding distance increases by 4×

... or the new skidding distance = Dƶ = 4  •  (20) = 80 meters

Physics question HW help?

We have to find Santa's gravitiational acceleration that is pointed down the slope:

On a 25* incline, gravity can be broken down into two components: towards the incline, and down the incline. On a flat plain (0* angle), gravity is directed 100% into the surface, while on a vertical wall (90* angle), gravity is 100% down.A 25* angle is closer to a flat plain than a vertical wall.

Anyways, we can find the component of gravity directed into the incline with g*cosX, where X is the angle of incline. Likewise,the component of gravity directed down the incline is g*sinX.

We are interested in the component of gravity going down the incline, which is:
g*sinX = (9.81 m/s/s)*sin25 = 4.15 m/s². This shows that any object on a frictionless incline of 25* will accelerate at 4.15 m/s².

We can now use the formula:

v² = v0² + 2ad
v² = 2(4.15 m/s/s)(7 m)
v = 7.6 m/s

Need help with 2 physics questions for hw?

not asking for answers i like doing my own work, im just stuck in not knowing which formulas to use
please if u can supply me with the formulas that would be great thanks

20.0 L of a monatomic ideal gas at a pressure of 100 kPa expand adiabatically until the volume doubles. What is the pressure in the gas at that point?
A) 31.5 kPa

and
An ideal gas undergoes the process a b c as shown in Figure. Pa = Pc = 240.0 kPa, Vb= Vc = 40.00 L, Va = 15.00 L, and Pb = 400.0 kPa. How much work is done by the system in this process?
a)2000j
this one comes with a graph that is similar to the one in this website where the axis are P vs V
http://www.tutornext.com/system/files/u22/right-triangle.jpg

Physics Homework Question ??? Need Help !!!?

Need help on these Physics homework questions! In summer school taking physics.

1) What water pressure must a pump that is located on the first floor supply to have water on the thirteenth floor of a building with a pressure of 35 lb/in2. Assume tha the distance between each floors is 10ft.

2) The area of the large piston in a hydraulic jack is 25.5cm2. The area of the small piston is 12cm2.
(a) what force must be applied to the small piston is a weight of 800N is to be lifted?

Need help with Physics HW?

Quite simply because as indicated by its name, an 'Alternating Current' produces, well, and alternating current, that is a current that is constantly changing between +ve and -ve. This is what is needed to create an alternating magnetic field around the coil, and induce a voltage in the secondary coil. If a 'Direct Current' was used, that is a current with one +ve or -ve state, an alternating magnetic field would not be created and no voltage would be induced in the transformer.

Need help w/ Physics HW!?

v^2 = u^2 + 2as => 0^2 = 10^2 - 2gs therapy for s. Upward adventure: v=u+at => 0=10-gt detect t. call it t1. with the aid of very fact the ball will return to the balcony factor on an same velocity it left, i.e. 10m/s: s=ut + 0.5at^2 15=10t + 0.5gt^2 therapy for t. call it t2 complete time= 2*t1 + t2

HW Physics -- Need help?

5.) even as artwork is performed through a stress on an merchandise, if the object is at relax, the speed of the object differences, because artwork motives a replace in speed. artwork is the capacity transferred to flow an merchandise a particular distance, consequently, if the object isn't transferring, and artwork is performed, the object starts gaining speed. even if, if the object replaced into transferring, artwork performed gained't replace speed if stress is kept consistent, so A is out. C is out, because the object ought to exert an opposing stress on the stress exerted on it, even if it won't be able to make that stress flow a distance (as an instance, once you're pushing a small timber block, the block won't be able to make your hand flow decrease back), so the object gained't do any artwork in any respect. D is out, because the object can flow horizontally by using artwork. E is out, because artwork performed on a merchandise through a stress motives the move of inner capacity from the object to the ecosystem through specifically warmth. So what's left is B. 6.) E is the answer. Mechanical capacity is the sum of the object's kinetic and capacity capacity, so on a frictionless floor, it truly is often the same, because the sum of both remains the same, even even as there is none of one in each and every of them. as an instance, if an merchandise has 10J of mechanical capacity, it ought to have 10J of kinetic/ 0J of capacity or vice-versa, even if both energies will consistently upload as a lot as 10J. even if, on a tricky floor, countless the kinetic capacity, by using friction, will be lost as warmth, so part of the mechanical capacity is lost as warmth, so mechanical capacity decreases. 7.) artwork = stress x displacement x the cosine of the attitude between both vectors (stress and displacement are vector parts.) for the reason that Jim ought to no longer flow the 100kg table in any respect, there is not any displacement, so the artwork performed through Jim is the same as 0. Virgil moved the 60kg table 2m interior the route of the stress, consequently artwork performed through Virgil = four hundred N x 2m x cos 0 (there is not any attitude between stress and displacement by using having the same route) = 800 Nm = 800 J Mik moved the 50kg table 4m interior the route of the stress so artwork performed through Mik = 200N x 4m x cos 0 = 800 J So the answer is D

Need help with Physics Homework?

I was absent when my teacher taught what the homework was about, and she is still making me do it! I've done most of the questions, there are just some i cant do. Any help?

Q// The Current through a 12 V Lamp when it is connected to a 12 V battery is 2.0 A. Calculate the resistance of the lamp at this Current.

Q/ The current through a 12 ohms resistor in an electric circuit is 1.5 A. Calculate the potential difference across the resistor.

Q// A 50 ohms resistor in an electric circuit has a potential difference across it of 20 V. Calculate the current through the resistor.

Q// A resistor in a circuit has a current through it of 0.20 A. When the potential difference across it is 15 V. Calculate the resistance of the resistor.

Thankyou to anyone who answers this. I've been ragging my brain out for an hour on these questions.