Physics Answers

 If 528 kJ of heat are added to 2.25 kg of helium at constant volume process when the initial temperature is 40 deg. C, find:

a) the final temperature in deg. C

b) the change in enthalpy in kJ

c) the change in entropy in kJ/K

A basketball is shot through the air, hitting the backboard of a hoop. During the shot, the basketball was travelling at 8 m/s, and right after hitting the backboard, the basketball travels 1 m/s in the opposite direction. The mass of a standard basketball is 590g.

a. Find the kinetic energy of the basketball before hitting the backboard (2pts)

b. Find the kinetic energy of the basketball after hitting the backboard (2pts)

1. The speed of light in a material is 0.52c. What is the critical angle of a light ray at the interface between the material and a vacuum?

Calculate the final volume of 0.4 m³ of an experimental gas which is compressed according to the law PV^y=C the initial gas pressure is increase by factor of seven and γ=1.5 give the answer to 4 decimal places 

Calculate the permitted energies of an electron confined in a box 1Å wide?

find electric field of all regions

+sigma =2c ------------------

E=3

-sigma =2c -------------------

A flat (unbanked) curve on a highway has a radius of 220.0 m. A car rounds the curve at a speed of 25 m/s. (a) What is the minimum coefficient of friction that will prevent sliding?

 A sled with a mass of 25.0 kg rests on a horizontal sheet of essentially frictionless ice. It is attached by a 5.00-m rope to a post set in the ice. Once given a push, the sled revolves uniformly in a circle around the post. If the sled makes five complete revolutions every minute, find the force F exerted on it by the rope.

A particle moving along the x-axis in simple harmonic motion starts from the equilibrium position, the origin, at time t=0 and moves to the right. The position of the particle after time, t, is given by the following equation: x=2.0 sin 3πt m

Calculate:

A) the maximum velocity of the motion

B) the acceptation of the object after 2 seconds

C) the distance traveled by the particle from t=0s to t=2s

The intensity of a sound wave at a distance of 5 m from the point source is 0.8 Wm⁻² . What will the intensity be at a distance of 10 m from the source?