Physics Answers

A student does 1.6 104J of work. In the process, his internal energy decreases by 4.23 104 J. Determine a) W b) DU c) Q

At 88 meters high a rock is thrown horizontally from the top of a cliff, with a horizontal speed of 25 m/s. Now, what's the direction of velocity and with what velocity does the rock hit the ground?

What is the horizontal force needed to accelerate a 42 kg grocery cart from rest to a velocity of 0.80 m s in 1.75 s

What is the horizontal force needed to accelerate a 42 grocery cart from rest to a velocity of 0.80 m/s in 1.75s

A closed gaseous system undergoes a reversible process during which 25 BTU are rejected, the volume changing from 5 ft3 to 2 ft3, and the pressure remains constant at 50 psia. Find the change of internal energy.

An electric kettle is connected to a 120-V

outlet and has 11.5 A of current flowing

through it. What is the resistance in the

kettle?

a stone thrown from the top of the building is given initial velocity off 20m/s streight upwards, the stone is launched 50m above the ground and the stone just misses the edge of the roof on its way down using ta = 0

Light travels from air into an optical fiber with an index of refraction of 1.44. 

(a) In which direction does the light bend? (b) If the angle of incidence on the

end of the fiber is 22 o , what is the angle of refraction inside the fiber? (c) 

Sketch the path of light as it changes media.

A golf ball travels at 16 m/s while a baseball moves at 7 m/s. The mass of the golf ball is 0.045kg and the mass of the baseball is 0.14kg. Which has a greater momentum?

A truck travelling at 22.5m/ decelerates at 2.27m/s².

How far does it travel during the third second when brakes are applied?