Get Expert Answers to Advanced Physics Questions

The unit of force in the SI system is the newton (N), which is defined in terms of basic SI units as $1N=1kg\cdot <!--\; \cdot \; -->m/s^2$. The unit of force in the British system is the pound (lb), which is defined in terms of the slug (British unit of mass), foot (ft), and second (s) as $1lb=1\text{slug }\cdot <!--\; \cdot \; -->ft/s^2$.
Find the value of 15.0N in pounds. Use the conversions $1slug=14.59kg\text{ and }1ft=.3048m$

Why is $(\text{kg}\cdot <!--\; \cdot \; -->{\text{m}}^2)/\text{s}$ written as "Joule second" when there is no joule present, and time is divided and not multiplied?

How is a simple harmonic motion affected by resistive forces? In this case, a spring block system is placed on rough horizontal surface. How to derive the block's displacement equation?

In basic high school physics/calculus you learn that you can formulate equations for velocity and displacement under constant acceleration as:
$a(t)=a_0$
$v(t)=a_{0}t+v_0$
$x(t)=\frac{1}{2}{a}_0{t}^2+v_{0}t+x_0$
My question is how would you formulate a similar equation when acceleration is dependent on the inverse-square of distance from a point, such as Coulomb's Law or Isaac Newton's inverse-square law of universal gravitation?

How can we say that a body is doing circular motion while doing a non uniform circular motion if the centripetal force is changing?

1) The parallel axis theorem provides a useful way to calculate the moment of inertia I about an arbitrary axis. The theorem states that $I=Icm+M{h}^2$, where Icm is the moment of inertia of the object relative to an axis that passes through the center of mass and is parallel to the axis of interest, M is the total mass of the object, and h is the perpendicular distance between the two axes. Use this theorem and information to determine the moment of inertia ($kg\cdot <!--\; \cdot \; -->m^2$) of a solid cylinder of mass M = 2.50 kg and radius R = 2.50 m relative to an axis that lies on the surface of the cylinder and is perpendicular to the circular ends.
2) A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 231-mile trip in a typical midsize car produces about $2.97\times <!--\; \times \; -->109J$ of energy. How fast would a 45.3-kg flywheel with a radius of 0.209 m have to rotate to store this much energy? Give your answer in rev/min.
3) Starting from rest, a basketball rolls from the top to the bottom of a hill, reaching a translational speed of 6.5 m/s. Ignore frictional losses. (a) What is the height of the hill? (b) Released from rest at the same height, a can of frozen juice rolls to the bottom of the same hill. What is the translational speed of the frozen juice can when it reaches the bottom?
4) A playground carousel is rotating counterclockwise about its center on frictionless bearings. A person standing still on the ground grabs onto one of the bars on the carousel very close to its outer edge and climbs aboard. Thus, this person begins with an angular speed of zero and ends up with a nonzero angular speed, which means that he underwent a counterclockwise angular acceleration. The carousel has a radius of 1.69 m, an initial angular speed of 3.22 rad/s, and a moment of inertia of $121kg\cdot <!--\; \cdot \; -->m^2$. The mass of the person is 45.0 kg. Find the final angular speed of the carousel after the person climbs aboard.
Ive tried figuring these out but i need help

Light bulb is rated $3.0V/1.5W$. The right wire of the circuits, which is 10 cm long, is pulled across with a constant speed v through a perpendicular magnetic field of strength 0.10 T.
(a) What speed must the wire have to light the lightbulb at its full brightness?
(b) What force is needed to keep the wire moving?

The formula to convert from Celsius to Fahrenheit is $F=1.8C+32$. Use this formula to complete the statements below. Round your answer to the nearest tenth as needed.
If the temperature is 73 F, that is equivalent to _C
If the temperature is 36C, that is equivalent to _F

Sam is driving his car at 55mi/h. He needs to keep his car within 5mi/h or his current speed.
Write and solve an absoulte-value equation to find Jason's maximum and minimum speeds.

Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?

The mean weight of 240 students in the second year class of a college is 88 kg. If the mean weight of boys and that of girls in the class are 90kg and 80 kg respectively, then what is the number of boys and girls in the class?

The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 8 minutes, then the area of the park (in sq. m) is:

Bob sets the thermostat in his apartment to 68 degrees. The actual temperature in his apartment can vary from this by as much as 3.5 degrees. Write an absolute-value equation that you can use to find the minimum and maximum temperature. Then find the minimum and maximum (solve this equation)

A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:

Monthly normal rainfall data (x , y) for a particular city are (2 , 6.68), (6 , 1.66), (8 , 2.83), where x represents time in months (with x = 1 representing January) and y represents rainfall in inches. Find the values of a, b, and c such that the equation y = ax^2 + bx + c models this data. According to the model, how much rain should the city expect during September?