Physics

Force question! (physics)

You pull a heavy 300 kg crate across a level floor with a rope that makes a 20 degree angle with the floor. The crate moves horizontally with constant velocity. The coefficient of kinetic friction is

How is it not possible for the laws of thermal dynamics to never go beyond a closed system

If the laws of thermal dynamics only work on a closed system how is that possible? It happens everywhere all the time. Even our sun and countless others all are in a state of entropy. Everything must

Difference between velocity and speed

velocity is a vector meaning it has both size and direction so changing direction means changing velocity even if your speed isnt changing and speed is scalar as it only include size of the speedcha

Physics: The distance from the center of a merry-go-round before it tips over

A block of wood 45 cmwide and 89 cm tall is placed on a merry-go-round which rotates at 0.88 rad/s. How far from the center may the block be placed before it will tip over? The acceleration of gravity

Need help with physic problem....

Hello, I am preparing for my physics finals. I am working on the study guide and I am not sure if I solve the last problem correctly. Can someone please let me know if I did correctly solve it. If I d

Physics question, seems easy but cant solve it

Two newly discovered planets follow circular orbits around a star in a distant part of the galaxy. The orbital speeds of the planets are determined to be 44.8 km/s and 50.9 km/s. The slower planets or

Calculate the energy it takes to accelerate a person ..

and a bicycle of total mass 75kg to 20 mph(8.9m*s^-2)...starting from from rest and ignoring friction and wind resistence.... you are supposed to use the kinetic energy equation Ek=1/2*mv^2-W = ΔKE= 1

Easy physics problem help solving it

An electron is a subatomic particle (m = 9.11 x 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +8.28 x 105 m/s to a final

Question on the first law of thermodynamics

Full Question: The internal energy of a gas inside a piston decreases by 195 J. If 52 J of work is done by the gas, how much energy is transferred by heat? Does heat add energy to or remove energy fro

Physics 12 - Vectors (Diagram provided)

Diagram: http://i56.tinypic.com/rwq6oi.jpg 1. Given the vectors A and B, determine B - A. 2. Determine A - B without using your answer in number 1. Then compare your results and see if they are oppos

A transformer for charging a power tool steps the line voltage down to 2.9 V.

The output current of this transformer is 240 mA. If the transformer is 80% efficient, what is the input current? A)7.3 mA B)240 mA C)4.6 mA D)190 mA E)300 mA If you could walk me through the st

A certain part of the electromagnetic spectrum ranges from 200 nm to 400 nm.

What is the highest frequency associated with this portion of the spectrum? A)7.50 × 1014 Hz B)7.50 × 1015 Hz C)1.50 × 1015 Hz D)7.50 × 1013 Hz E)1.50 × 1014 Hz-none of your answers are correct, b

Physics: Where did the energy go

A lab experiment for the conservation of energy theory resulted in E-initial being 0.625 and E-final being 0.610, therefore a 2.4% energy loss results.If the theory is that energy is neither created n

The internal energy of a system is initially 27 J. A total of 33 J of energy is added to the system by heat...

1. The internal energy of a system is initially 27 J. A total of 33 J of energy is added to the system by heat while the system does 26 J of work. What is the systems final internal energy? here are

An electron moving perpendicular to a magnetic field of 2.2 × 10-2 T moves in a circle of certain radius.

If the electron is moving with a speed of 1.5 × 107 m/s, what is the radius of the circle? A)1.5 × 10-3 m B)3.9 × 10-3 m C)2.2 × 10-4 m D)3.9 × 10-4 m E)2.2 × 10-3 m I would love an explanation!-