1. A 12m window hanging scaffolding basket supporting an 80Kg man and paint material? The scaffolding is hanging by a steel rope at eacch end. The basket weight is 40 Kg, the paint is 25Kg located at the middle. The man is located at the middle.

1. Draw the forces diagram.

2. What are the forces F1 and F2 at the ropes holding the basket at the ends?

b) The man moves 4 meters towards F2, will F1 & F2 change?    

c) Find the new F1 & F2 forces exerted on the scaffolding in b above. ∑Ƭ cw=∑Ƭccw & Ƭ=Fd?

2. Two cars of equal weights of (1400lb each) were subject to an inelastic head-on collision. One car was traveling eastbound at 50mi/h speed and the other car was traveling westbound at 60mi/h speed.   

1. What was the direction of the motion after collision?         

2. What was the speed after collision? m1V1+m2V2=(m1+ m2)V’ ;  

3. How far they went after 1.4 seconds? convert V to ft/s; S=(V)’.(t)

3. Two men exert 115 lb force each to push a car for distance of 150 feet.

1. What is the Work done in lb ft? W=F.S   

2. What is the power exerted after 5 minutes? P=W/t  

3. If the road is at an angle of 15o uphill. What is the mechanical advantage of the road?

4. What is the force of the effort required to move the 1000lb car the 150 ft in c above?

4. A submersible gasoline pump was used to lift 210 gallons/min of gasoline from the bottom of a tank 20 ft below ground level. (One gallon gasoline is 6.3 lb)

1. What is the power rating of the submersible pump? P=W/t= F.S/t    

2. How many gallons can be lifted in 10 minutes?   

5. A 1000 lb box was moved using inclined plane (h=5ft and L=20ft: MA=L/h), a wheel and axle simple machine (wheel diameter is 2 ft and the axle is 0.5 ft: MA=D/d) and 3 pulleys with 3 movables strands.

1. Find the Mechanical Advantage of the inclined plane and the wheel and axle

2. Find the MA of the system (MA = MA1 x MA2 x MA3)

3. Find the exerted effort.

6. True or False questions.

Sitting in a second-story apartment, a physicist notices a ball moving straight upward just outside her window. The ball is visible for 0.24 s as it moves a distance of 1.18 m from the bottom to the top of the window.How long does it take before the ball reappears?What is the greatest height of the ball above the top of the window?

Imperial Building has height of 73 m. Three snipers on a nearby roof shut with three rifle when King Kong jumped down (free fall).
1.
The sniper A shut with initial velocity 20 m/s and angle 30 degree, the horizontal distance from the sniper A to the base of imperial building is 40 m. The roof is 50 m tall.
2.
The sniper B shut with initial velocity 10 m/s and angle 60 degree, the horizontal distance from the sniper B to the base of imperial building is 30 m. The roof is 60 m tall.
3.
The sniper C shut with initial velocity 30 m/s and angle 20 degree, the horizontal distance from the sniper C to the base of imperial building is 50 m. The roof is 70 m tall.

Do a careful investigation, find out Who shut King Kong

An AC generator supplies an rms voltage of 240 V at 50.0 Hz. It is connected in series with a 0.350 H inductor, a 3.60 μF capacitor and a 211 Ω resistor.

1. What is the impedance of the circuit?

2. What is the rms current through the resistor?

3. What is the average power dissipated in the circuit?

4. What is the peak current through the resistor?

5. What is the peak voltage across the inductor?

6. What is the peak voltage across the capacitor?

7. The generator frequency is now changed so that the circuit is in resonance. What is that new (resonance) frequency?

Explain conservation of momentum and give examples in daily life.

In your own words, explain impulse and give examples in daily life.

In your own words, center of mass and give examples in daily life

please reply in text! (not handwritten)

Two point charges, Q1 = 3.3?C and Q2 = -1.5?C ,are placed on the x axis. Suppose that Q2 is placed at the origin, and Q1 is placed at the coordinatex1 = ? 6.0cm (Figure 1) .

Part A:

At what point(s) along the x axis is the electric field zero? Determine the x-coordinate(s) of the point(s).

Express your answer using two significant figures. If there is more than one answer, enter your answers in ascending order separated by commas.

Part B:

At what point(s) along the x axis is the potential zero? Determine the x-coordinate(s) of the point(s).

Express your answer using two significant figures. If there is more than one answer, enter your answers in ascending order separated by commas.

A series ac circuit contains a 210 Ω resistor, a 20.0 mH inductor, a 3.30 μF capacitor, and an ac power source of voltage amplitude 45.0 V operating at an angular frequency of 360 rad/s . 1)What is the power factor of this circuit? 2)Find the average power delivered to the entire circuit. 3)What is the average power delivered to the resistor, to the capacitor, and to the inductor?

A dielectric-filled parallel-plate capacitor has plate area A = 25.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 2.00. The capacitor is connected to a battery that creates a constant voltage V = 12.5 V . Throughout the problem, use ϵ0 = 8.85×10⁻¹² C2/N⋅m2 .

PART A:

U₁ was found:

PART B:

The dielectric plate is now slowly pulled out of the capacitor, which remains connected to the battery. Find the energy U2 of the capacitor at the moment when the capacitor is half-filled with the dielectric.

Express your answer numerically in joules.

PART C:

The capacitor is now disconnected from the battery, and the dielectric plate is slowly removed the rest of the way out of the capacitor. Find the new energy of the capacitor, U3.

Express your answer numerically in joules.

PART D:

In the process of removing the remaining portion of the dielectric from the disconnected capacitor, how much work W is done by the external agent acting on the dielectric?

Express your answer numerically in joules.

Two small nonconducting spheres have a total charge of Q=Q1+Q2= 90.0 μC , Q1<Q2. When placed 31.0 cm apart, the force each exerts on the other is 13.0 N and is repulsive.

Part A: What is the charge Q1?

Part B: What is the charge Q2?

Part C: What would Q1 be if the force were attractive?

Part D: What would Q2 be if the force were attractive?

In areas of enhanced heat flow, geothermal heating can be used to supply heating to homes, either by using ground water directly or by placing a water reservoir at depth. In Iceland, where the average temperature over the year is 4.6ºC, the geothermal flux can be as high as 300 mW m-2.

(a)

If you wanted to be able to supply a home with indoor temperature at 25ºC and water at a temperature of 55ºC, how deep would your reservoir need to be?

(b)

Why might Iceland have such a high geothermal flux compared to other areas?

(c)

Does high geothermal flux accelerate the melting of ice sheets, why or why not?

A convex mirror has a focal length of -58.0 cm. A 12.0-cm-tall object is located 58.0 cm in front of this mirror. Determine the (a) location and (b) size of the image.

How is a panel study different from a pilot study? (8-10 sentences)

light travels from air through two layers with index of refraction n1 and n2, respectively. If upon entering each layer light loses 10% of its velosity, what is the index of refraction n2

3.) To maintain a constant speed, the force provided by a car's engine must equal the drag force plus the force of friction of the road (the rolling resistance). Assume all values are accurate to three significant digits. (Assume the density of air is 1.21 kg/m³.)

A.) What is the magnitude of drag force (in N) at 58 km/h and 116 km/h for a Toyota Camry? (Drag area is 0.70 m², and drag coefficient is 0.28.)

B.) What is the magnitude of drag force (in N) at 58 km/h and 116 km/h for a Hummer H2? (Drag area is 2.44 m², and drag coefficient is 0.64.)

How much heat is required to change a 30.2 g ice cube from ice at -13.8°C to water at 23°C? (if necessary, use c_ice=2090 J/kg°C and c_steam= 2010 J/kg°C)

How much heat is required to change a 30.2 g ice cube from ice at -13.8°C to steam at 120°C?