a) If 8.00 hp are required to drive a 1800-kg automobile at 54.0 km/h on a level road, what is the total retarding force due to friction, air resistance, and so on?

b) What power is necessary to drive the car at 54.0 km/h up a 10.0% grade (a hill rising 10.0 m vertically in 100.0 m horizontally)?

c) What power is necessary to drive the car at 54.0 km/h down a 1.00 % grade?

d) Down what percent grade would the car coast at 54.0 km/h ?

A 0.0038 kg leaf falls 16.8 m to the ground, where it lands with a speed of 12.2 m/s. What was the average force of air resistance on the leaf while it was falling?

Problem 1: In the figure to the right, m1=20.0kg and α=53.1o . The coefficient of kinetic friction between the block and the incline is µk=0.40. a) What must be the mass m2 of the hanging block if it is to descend 12.0 m in the first 2.00 s after the system is released from rest? b) For the µk in the problem, what mass m2 will provide constant velocity of m1 down the incline? c) Suppose µs is 0.7, what is the maximum mass m2 that will still cause no movement?

For physics discussion post. Please TYPE the response as I struggle with reading written information.

• Explain Boyle's law, Charles law, and the Ideal Gas equation.
• Explain Kinetic Molecular Theory of Ideal Gas.
• In your own words, explain the First Law of Thermodynamics and give examples.
• In your own words, explain adiabatic process and isothermal process, and give examples.

Vector A = (-2, 2.4) and vector B = (4, 2.3). Find the magnitude of the component of A perpendicular to the direction of B

A stone is dropped at t = 0. A second stone, with 6 times the mass of the first, is dropped from the same point at t = 130 ms. (a) How far below the release point is the center of mass of the two stones at t = 350 ms? (Neither stone has yet reached the ground.) (b) How fast is the center of mass of the two-stone system moving at that time?

A) At a temperature of 27 ?C, what is the speed of longitudinal waves in hydrogen (molar mass 2.02 g/mol)? The ratio of heat capacities for hydrogen is ?=1.41.

B) At a temperature of 27 ?C, what is the speed of longitudinal waves in helium (molar mass 4.00 g/mol)? The ratio of heat capacities for helium is ?=1.67.

C)

At a temperature of 27 ?C, what is the speed of longitudinal waves in argon (molar mass 39.9 g/mol)? The ratio of heat capacities for argon is ?=1.67.

D,E, F i need help please and show work please

D)Compare your answer for part A with the speed in air at the same temperature. The ratio of heat capacities for air is ?=1.40.

E)Compare your answer for part B with the speed in air at the same temperature. The ratio of heat capacities for air is ?=1.40.

F)Compare your answer for part C with the speed in air at the same temperature. The ratio of heat capacities for air is ?=1.40.

In an engine, a piston oscillates with simple harmonic motion so that its position varies according to the expression x(t) = 15.0 cos(20.0t) where xis in centimeters and t is in seconds. At t = 1 s, find (a) the position of the piston, (b) its velocity, and (c) its acceleration. Find (d) the period and (e) the amplitude of the motion. (f) Sketch a plot of the acceleration as a function oftime. Scale the plot properly.

A woman stands on a scale in a moving elevator. Her mass is 61.0 kg, and the combined mass of the elevator and scale is an additional 725 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force of 9340 N. What does the scale read (in N) during the acceleration?

1- Block 1 (mass 2.0 kg) is moving to right at speed of 5.0 m/s. It collides with block 2 (mass 3.0 kg) that is moving to the right at speed of 3.0 m/s.

a) What is the speed of the blocks if the collision is completely inelastic? How much kinetic energy is lost? (3.8 m/s, 2.4 J)

b) What is the final speed of the blocks if the collision is elastic? (v1 = 2.6 m/s, v2 = 4.6 m/s)

2 - A solid uniform sphere of mass 5.0 kg and diameter 40 cm, rolls down a hill without slipping. If the velocity of the sphere downhill is 2.0 m/s.

a) what is the height of the hill? (29 cm)

b) What is the angular momentum of the sphere downhill? (0.8 kg*m/s)

I know the answers I just need to know how to get to those answers!

A passenger with mass 85 kg rides in a Ferris wheel. The seats travel in a circle of radius 35 m. The Ferris wheel rotates at constant speed and makes one complete revolution every 25 s.

A)

Calculate the magnitude of the net force exerted on the passenger by the seat when she is one-quarter revolution past her highest point.

B)

Calculate the direction of the net force exerted on the passenger by the seat when she is one-quarter revolution past her highest point.

I need exact answers. Thank you

A football receiver running straight downfield at 5.20 m/s is 10.5 m in front of the quarterback when a pass is thrown downfield at 23.0° above the horizon (see the figure below).

If the receiver never changes speed and the ball is caught at the same height from which it was thrown, find the football's initial speed, the amount of time the football spends in the air, and the distance between the quarterback and the receiver when the catch is made.

(a) the football's initial speed (in m/s)

___________ m/s

(b) the amount of time the football spends in the air (in s)

________________ s

(c) the distance between the quarterback and the receiver when the catch is made (in m)

_____________m

A beam of electrons is shot into a uniform downward electric field of magnitude 1.11x10^3 N/C. The electrons have an initial velocity of 1.02x10^7 m/s, directed horizontally. The field acts over a small region, 5.00 cm in the horizontal direction.

(a)Find the magnitude and direction of the electric force exerted on each electron.
-magnitude:
-direction:

(b) How does the gravitational force on an electron compare with the electric force?

   -The gravitational force is much smaller than the electric force. OR -The gravitational force is much larger than the electric force.

(c) How far has each electron moved in the vertical direction by the time it has emerged from the field?

(d) What is the electron's vertical component of velocity as it emerges from the field? (Up is the positive y-direction.)

(e) The electrons move an additional 19.8 cm after leaving the field. Find the total vertical distance that they have been deflected by the field.

A 0.600 kg block is attached to a spring with spring constant 18.0 N/m . While the block is sitting at rest, a student hits it with a hammer and almost instantaneously gives it a speed of 40.0 cm/s . What is the block's speed at the point where x= 0.550 A?

Very short pulses of high-intensity laser beams are used to repair detached portions of the retina of the eye. The brief pulses of energy absorbed by the retina welds the detached portion back into place. In one such procedure, a laser beam has a wavelength of 810 nmand delivers 250 mW of power spread over a circular spot 510 μm in diameter. The vitreous humor (the transparent fluid that fills most of the eye) has an index of refraction of 1.34.

Part A

If the laser pulses are each 1.50 ms long, how much energy is delivered to the retina with each pulse?

Express your answer with the appropriate units.

Part B

What average pressure would the pulse of the laser beam exert at normal incidence on a surface in air if the beam is fully absorbed?

Express your answer with the appropriate units.

Part C

What are the wavelength of the laser light inside the vitreous humor of the eye?

Express your answer with the appropriate units.

Part D

What is the frequency of the laser light inside the vitreous humor of the eye?

Express your answer with the appropriate units.

Part E

What is the maximum value of the electric field in the laser beam?

Express your answer with the appropriate units.

Part F

What is the maximum value of the magnetic field in the laser beam?