A 1.5 kg block of wood is launched up a wooden ramp that has a 40-degree incline. The initial speed of the block is 12 m/s. The coefficient of static friction is 0.4 and the coefficient of kinetic friction is 0.20. Ignore air resistance.
A) Draw the incline with the block at the bottom of the ramp and at the top of its slide. Label with a coordinate system. List all known quantities.
B) Draw free body diagrams for the block sliding up the incline and down the incline. Label all forces and acceleration.
C) What is the normal force on the block?
D) What is the acceleration as the block moves up the ramp?
E) How far up the ramp does the block travel?
F) What is the static frictional force on the block when it stops? Is it enough to hold the block there?

A nearsighted man uses his ideally prescribed eyeglasses that have a refractive power of −2.60 diopters. He would like a prescription for contact lenses. What is the correct contact lens prescription if he normally wears his eyeglasses a distance of 2.7 cm from his eyes?

Astronomy Mysteries Today

1.what’s dark matter? Why do astronomers believe it exists?

2. what’s dark matter? Why do astronomers believe it exists?

3. What’s a black hole? What’s the difference between stellar balck hoiles and galaxy black holes? Why is it black?

4. People ask “who” made the original mass that expanded in the Big Bang. What is one natural, as contrasted with supernatural, explanation for how the world began?

5. What may have been the first particles formed… before protons and neutrons, before atoms, before elements, before molecules?

The Hyundai Blue-Will Plug-In hybrid is a compact 4-door, 4-seat sedan.It is a test bed of new ideas, including panoramic glass roof with solar
cells for recharging batteries, a thermal generator that converts hot exhaust gases into electricity, drive-by-wire steering, lithium polymer
batteries, and touch screen controls. Blue-Will promises an EV driving range up to 40 miles on a charge and an economy rating up to 100 mpg.
Helping to achieve those numbers is a direct injection 1.6 liter 152-hp four, a CVT and a 100 kw electric motor..

1. A Hyundai Blue-Will hybrid is capable of an acceleration of 4.3 m/s. It has a mass of 770 kilograms of steel, 180 kilograms of iron, 110 kilograms of plastics, 80 kilograms of aluminum, 60 kilograms of rubber, 20 kilograms of glass, and 8 kilograms of other materials. The driver has a mass of 85 kg. a Sketch the system of the Blue Will b.Sketch the system of the driver c. What is the force on the driver from the acceleration? d.Compare the force of the car on the driver to the driver’s weight, using a ratio. 2. The Hyundai Blue Will hybrid is driving at a velocity of 125 kph, and crashes into another car traveling at a velocity of 35 kph. Assuming the drivers are of comparable mass, and the car bumpers lock on impact: a. What is the final velocity of the cars? b. If the famous Blue Will crashes into a tree, instead, in 2.6 seconds, what is the impulse? c. What is the total force exerted by the tree in stopping the Blue Will? 3. The Famous Blue Will hybrid is being driven at a velocity of 75 kph when the driver sees a tree ahead. a. The driver locks his brakes, causing the car to skid. The coefficient of friction of rubber on dry concrete is 1.0 (static) and 0.7 (kinetic). How much force will the brakes apply to the car? What difference would it make if the driver pumped the brakes? b. After 1.0 second of braking, what will be the car’s velocity? c. How far in advance will the driver need to start braking to avoid the tree? 4. The Hyundai has about the same drag as a Camry (about 0.36) and air has a density of about 1.21 kg/m3. The cross section of the Hyundai is about 1.5 m × 1.5 m. Take the torque provided by the engine at speed as about 250 lbf. a. What is the force applied by air resistance at 75 kph? b. Would this help the driver avoid hitting the tree in the previous problem? Why or why not? c. What is the maximum velocity of the car? Is this answer reasonable? Why or why not?

Holly Hiker goes for a walk which consists of three parts:

1: Walks 6.00km at an angle of 60.0 degrees west of north

2: sits for lunch for 30 minutes

3: Walks 4.00km at an angle of 75.0 degrees north of west for 45 mins ( or 0.75 hours)

a) draw a vector diagram showing Holly's walk. Include both legs and the resultant

b) Write the two walking legs of the trip in unit vector notation

c) Find Holly's displacement and average velocity( in both polar and unit vector notation)

Thanks so much in advance!!

a ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center the disk has mass md=2.6 kg and radius R=0.24 m the rods each has mass mr=1.4 kg and length L=0.75m1). what is the moment of inertia of each rod about the axis of rotation? 2). what is the moment of inertia of the disk about the axis of rotation? 3).what is the moment of inertia of the whole ceiling fan? 4).when the fan is turned on it takes t=3.6 s and a total of 12 revolutions to accelerate up to its full speed what is the magnitude of the angular acceleration? 5). what is the final angular speed of the fan? 6). what is the final rotational energy of the fan? 7).now the fan is turned to a lower setting where it ends with half of its rotational energy as before the time it takes to slow to this new speed is also t=3.6 s what is the final angular speed of the fan? 8). what is the magnitude of the angular acceleration while the fan slows down?

A curve of radius 73 m is banked for a design speed of 75 km/h . If the coefficient of static friction is 0.39 (wet pavement), at what range of speeds can a car safely make the curve?  [Hint: Consider the direction of the friction force when the car goes too slow or too fast.] Express your answers using two significant figures separated by a comma. (v min, v max in km/h)

1) a. consider a ball of m= 0.50kg. does it take the same amount of additional energy to vertically lift it from 25cm to 30cm as it does to lift from 30cm to 35 cm? if not, which takes more. Why?

b. does it take the same amount of additional energy to speed your car (mass m=1000 kg) up from 25m/s to 30m/s as it does to speed it up from 30m/s to 35m/s? if not which takes more? Why?

c. consider a spring with k=10N/m. Does it take the same amount of additional energy to stretch the spring from 25cm to 30 cm as it does to stretch it from 30cm to 35 cm? If not, Which takes more? why?

Please explain each part thanks!.

Question 9

Name the following unit of energy: the change in electric potential energy as an electron moves through a potential difference of one volt.

Joule (J)

Volt (V)

Electron volt (eV)

Watt (W)

.

question 10

.

Consider two charged particles situated as follows: One charge –2q is located on the y axis at a distance d from the origin, and the other charge –q is located on the x axis at a distance 2d from the origin. What is the total electric potential at the origin?

.

–2kq/d

–kq/(2d)

–5kq/(2d)

–kq/d

.

Question 13

Every point on an equipotential surface

.

is at zero electric potential.

is a a positive electric potential.

is at a negative electric potential.

is at the same electric potential.

.

Question 14

Which of the following statements concerning equipotential surfaces is true?

.

Electric field lines are directed parallel to these surfaces.

The electric potential on one equipotential surface is equal to that on all other equipotential surfaces.

The net work done by the electric force is zero when moving along an equipotential surface.

The net work done by the electric force in moving a charge from one equipotential surface to another is zero.

In the figure, a metal rod is forced to move with constant velocity along two parallel metal rails, connected with a strip of metal at one end. A magnetic field of magnitude B = 0.417 T points out of the page. (a) If the rails are separated by 34.5 cm and the speed of the rod is 48.6 cm/s, what is the magnitude of the emf generated in volts?(b) If the rod has a resistance of 26.4 ? and the rails and connector have negligible resistance, what is the current in amperes in the rod? (c) At what rate is energy being transferred to thermal energy?

1. What is the objective of this assignment?
2. Briefly explain the Doppler Effect.
3. Set both the listener velocity v_L and the source velocity v_S to -2 m/s. Run the demo. What is the value of the frequency f_L? Does it change or remain constant?
4. Set the listener velocity v_L to -2 m/s and the source velocity v_Sto -5 m/s. Run the demo. What is the value of the frequency f_L? Does it change or remain constant? If there is a change, when does it take place? Explain.
5. Set v_L = 0. Set v_S = -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, and 5 m/s
   
   For each of the above values of v_S, record the value of f_L. That should give you 11 data points, each point corresponding to one value of v_S and its corresponding value of f_L. Type the values of v_S in column A and the values of f_L in column B.
6. On an x-y graph, plot the values of f_L as a function of the values of v_S(f_Lvalues go on the vertical axis and v_S values go on the horizontal axis). Include this plot in your report.
7. Describe the curve of f_L versus v_S, and write a short conclusion.

A cat rides a merry go round turning with uniform circular motion. At time t1=2.00s, the cat's velocity is gives by Vx = 3.00 m/s and Vy = 4.00 m/s. At t2 = 5.00 s,the cat's velocity is give by Vx = -3.00 m/s and Vy = -4.00 m/s. Take the coordinate system of the merry go round to have its origin at the center.

(a) What is the magnitude of the cat's centripetal acceleration?

(b) What is the magnitude of the cat's average acceleration during the time interval t2-t1?

(c) Assuming uniform circular motion before t1, what would have been the x-y coordinate location of the cat at t0= 0.00 s?

(d) What angle relative to the positive y-axis does the centripetal acceleration vector point at t= 3.00 s?

A body moves along a straight line, its distance from the origin at any instant being given by the equation x = 8t − 3t^2, where x is in centimeters and t is in seconds.

(a) Find the average velocity of the body in the interval from t = 0 to t = 1 sec, and in the interval from t = 0 to t = 4 sec.

(b) Find the expression for the average velocity in the interval from t to t + Δt.

(c) What is the limiting value of this expression as Δt approaches zero?

(d) Find the time or times at which the body is at rest. (e) Find the expression for the acceleration at any time.Type or paste question here

The big prediction here is how the masses, the radius, the period, and the angle interrelate. Please predict the angle that the string makes below the horizontal (the angle of declination) for the following combinations of masses, radii, and periods:

m (whirling mass) = 0.010 kg

m (hanging weight) = 0.100 kg

radius = 1 meter period =

1 second per revolution