Questions
A projectile is fired from the ground, reaches a maximum height of 26.8 m and lands...

A projectile is fired from the ground, reaches a maximum height of 26.8 m and lands a distance of 76.7 m away from the launch point. What was the projectile s launch velocity?

A) 28.2 m/s, 54.4 degrees above horizontal

B) 22.9 m/s, 27.2 degrees above horizontal

C) 16.4 m/s, 16.3 degrees above horizontal

D) 42.3 m/s, 8.2 degrees above horizontal

In: Physics

A power line running East-West at 150kVAC carrying a 75MWatt load is 10 meters overhead. A...

A power line running East-West at 150kVAC carrying a 75MWatt load is 10 meters overhead. A thief makes a 100 turn loop of insulated copper wire around a plastic garbage can with a 70cm diameter. The voltage generated in this coil is used to charge batteries for a fish-finder, lights and radio in his fish hut. The battery charger is electrically equivalent to a 5 ohm resistor.

a) [2] What orientation of the garbage pail winding will allow the greatest rate of electricity theft?

b) [4] Determine the voltage generated across the battery charger.

c) [2] Residential power costs $0.10/kWh. What is the value of the power stolen per day.

d) [2] Why would metal can be a bad choice?


e) [4] Above the indication is that the other wire for the AC power transmission is very far away. In fact they both hang from the same structure. If each wire carries a 100amp current and they are separated by 50cm, determine the force per unit length on the wires

In: Physics

A woman lifts a 7.2-kg barbell in each hand with her arm in a horizontal position...

A woman lifts a 7.2-kg barbell in each hand with her arm in a horizontal position at the side of her body and holds it there for 3 s. The deltoid attaches 13 cm from the shoulder joint and makes a 13∘ angle with the humerus. The barbell in her hand is 0.55 m from the shoulder joint, and the center of mass of her 4.0-kg arm is 0.24 m from the joint.

1. Determine the magnitude of the force that the lifter's shoulder joint exerts on her humerus. Express your answer with the appropriate units.

2. Determine the direction of the force (measured clockwise from the positive x-axis) that the lifter's shoulder joint exerts on her humerus. Express your answer with the appropriate units.

I already found the force the deltoid exerts on the humerus (with help) but I am not sure how to even set up these problems. Any help is great, thank you!

In: Physics

A large punch bowl holds 3.30 kg of lemonade (which is essentially water) at 22.0 ∘C....

A large punch bowl holds 3.30 kg of lemonade (which is essentially water) at 22.0 ∘C. A 5.60×10−2-kg ice cube at -10.0 ∘C is placed in the lemonade.

Part A

What is the final temperature of the system? Ignore any heat exchange with the bowl or the surroundings.

T

T

=

nothing

  ∘C  

SubmitRequest Answer

Part B

What is the amount of ice (if any) remaining?

Express your answer using one significant figure.

m

m

=

nothing

  kg  

SubmitRequest Answer

Provide Feedback

In: Physics

On watching The Dark Knight (2008) again, I was struck with inspiration for a physics problem....

On watching The Dark Knight (2008) again, I was struck with inspiration for a physics problem. In their final confrontation, Batman throws the Joker off of a high building. Half-way down to the ground Batman launches his grapple gun and barely manages to hook Joker and prevent him from hitting the ground. If the building were 100 meters tall, how fast would the grapple gun need to be fired in order to catch the Joker before he hits the ground, assuming Batman waits until the Joker is half-way down to fire? As usual, ignore air resistance. How fast was Joker moving just prior to being bat-grappled?

In: Physics

A 150g ball slides down a perfectly smooth incline starting at a height of 2.44m, at...

A 150g ball slides down a perfectly smooth incline starting at a height of 2.44m, at rest. At the bottom of the incline is strikes and sticks to a 280g block. The block/ball combo are then free to move along a frictionless rollercoaster track. The first hill is only 23 cm high. Can it make it over this first hill? Defend your response with detailed analysis. If the combo CAN make it over the hill, how fast is it moving at the top of the hill?

In: Physics

Josh has just raised a 2.5 kg bucket of water using a well 's winch when...

Josh has just raised a 2.5 kg bucket of water using a well 's winch when he accidentally lets go of the handle. The winch consists of a rope wrapped around a 3 kg, 4-cm-diameter cylinder, which rotates on an axle through the center. The bucket is released from rest 4 m above the water level of the well.

A) How long does it take to reach the water?

B)What is the torque generated due to tension?

C) what is the angular acceleration of the cylinder due to this torque?

In: Physics

I need an equation to calculate how much time a coil has to and can remain...

I need an equation to calculate how much time a coil has to and can remain active in a coilgun to reach a specific velocity. In coilguns the coils must be disabled once the projectile is 1/2 inside the coil or the projectile will bounce.

Fixed variables are as follow:
-Mass of projectile
-Initial velocity of projectile assuming vacuum
-Final velocity of projectile assuming vacuum
-Projectile and coil length (Projectile length is equal to coil length
-Coil attraction distance in millimeters
-Coil amperage draw
-Voltage
-Efficiency

In: Physics

Magnetism is produced by circulating electric currents, but also by the spin of elementary particles and...

Magnetism is produced by circulating electric currents, but also by the spin of elementary particles and many atoms that are small magnets. An electric current I circulating in a wire of radius R, produces a magnetic field in the center of the wire of value B = u or I /) 2r). (uo - 1.26 x 10 ^ -6 T m / A).

We can use this formula as a model for three situations: the Earth, an atom of iron and the electron.

a) For Earth, R = 6,000 km and B = 5 x 10 ^ -4 T. Estimate the order of the current that is capable of generating this field.

b) For the iron atom, the magnetic field is produced by the electron of the last level, which is a charge of 1.6 x 10 ^ -19 C which circulates with the frequency of 10 ^ 16 Hz, in a radius of about 10 ^ -10 m. Calculate the order of the magnetic fields in the iron atom.

c) For the electron, the 1.6 x 10 ^ -19 C charge that rotates on itself. Assume that the turning radius is the order of R = 10 ^ -18m. The current is then of the order of e v / (2piR) = e f, where f is the frequency of rotation. Using this formula, calculate the value of B generated by the electron.

In: Physics

Draw the diagrams for the a)two-probe and b)four-probe measurement setups. (Include and label the sample being...

Draw the diagrams for the a)two-probe and b)four-probe measurement setups.
(Include and label the sample being measured, the correct input signal, and the correct
measures signal). c)Describe the circumstances under which each of the above measurement
schemes is to be used.

In: Physics

A curve of radius 30 m is banked so that a 950 kg car travelling at...

A curve of radius 30 m is banked so that a 950 kg car travelling at
40 km/h can go round it even if the road is so icy that the coefficient of static friction is approximately zero. You are commissioned to tell the local police the range of speeds at which a car can travel around this curve without skidding. Neglect the effects of air drag and rolling friction. If the coefficient of static friction is 0.3, what is the range of speeds you tell them?

In: Physics

A photographer in a helicopter ascending vertically at a constant rate of 15.0m/s accidentally drops a...

A photographer in a helicopter ascending vertically at a constant rate of 15.0m/s accidentally drops a camera out the window when the helicopter is 54.0m above the ground.

a)How long will the camera take to reach the ground?

b)What will its speed be when it hits?

In: Physics

Describe the lung cancer and how a CT scan has affected the diagnosis and/or treatment of...

Describe the lung cancer and how a CT scan has affected the diagnosis and/or treatment of this pathology over the years.

In: Physics

Comets travel around the sun in elliptical orbits with large eccentricities. If a comet has speed...

Comets travel around the sun in elliptical orbits with large eccentricities. If a comet has speed 1.8×104 m/s when at a distance of 2.6×1011 m from the center of the sun, what is its speed when at a distance of 5.2×1010 m

v=…..m/s

In: Physics

When a block is completely submerged under water, the buoyancy force on it is 11.8N; when...

When a block is completely submerged under water, the buoyancy force on it is 11.8N; when it is completely submerged under an unknown liquid, the buoyancy force is measured to be 7.8N. What is the density (in unit of kg/m3) of the unknown liquid?

When an object is completely submerged under water (LaTeX: \rho_{water}=ρ w a t e r =1000kg/m3,), the buoyancy force on it is 6.2N. If the object is completely submerged under a different liquid (LaTeX: \rho_{liquid}=ρ l i q u i d =781kg/m3,) what would be the buoyancy force on it (in unit of newton)?

In: Physics