That was litterally all of the information they gave to me. In the answer though they have:
m1v1 + m2v2 = m1v1` + m2v2`
(170g)(3.13m/s) + 0 = (170g)(-0.147 m/s) + (155g)(v2')
v2' = 3.59 m/s
I really just have no idea where they got the -0.147 m/s
Homework Statement
Mass of Cue stick : 595 g
Mass of White Ball: 170 g
Mass of Black Ball: 155 g
On the pool table, the white ball bounces off of the black ball and moves in the direction opposite to its original direction. If the speed of the white ball immediately after the collision is...
Homework Statement
Calculate the shortest wavelength photon that is emitted in the hydrogen atom.
Energy when n = 1 = -13.6 eV
Homework Equations
E = hc/λ
λ = hc/E
The Attempt at a Solution
Well as far as I understand, when the electron is in the n = 1 energy level it has it's...
Homework Statement
An electron in the 3rd stationary state around a hydrogen atom has an energy value of -1.512 eV. What will the electron's energy be if the hydrogen atom absorbs a photon with a wavelength of 1090 nm?
E = -1.512 eV
Homework Equations
Ephoton = hc/λ
The Attempt...
Homework Statement
In the hydrogen atom, the electron jumps from the n = 1 level to the n = 4 level.
a. During this transition from n = 1 to n = 4, is a photon emitted or absorbed?
b. What is the change in energy of the electron?
c. State the transition in words.
d. What is the wavelength...
Homework Statement
A 1.50 x 10^-14 kg oil drop accelerates downward at a rate of 1.80 m/s^2 when placed between two horizontal plates that are 9.40 ch apart. The potential difference between the two plates is 980 V. Determine the magnitude of the charge on the oil drop.
m = 1.50 x 10^-14 kg...
Homework Statement
How do the results of performing Young's experiment with x-rays and then high speed electrons support the wave-particle model?
The Attempt at a Solution
The experiment showed that an electron traveling at high speeds are capable of making interference patters, which is a...
Homework Statement
The scientist changes the frequency of the incident X-ray to 4.50 x 10^19 Hz and measures the deflected X ray frequency of 4.32 x 10^19 Hz. What was the angle of deflection?
Fi = 4.50 x 10^19 Hz
Ff = 4.32 x 10^19 Hz
Homework Equations
Δλ = λf - λi
Δλ =...
Homework Statement
An X-ray with a frequency of 3.74 x 10^20 Hz is incident on a thin piece of metal. The lower frequency X ray on the other side is observed deflected at 48°. What is the frequency fo the deflected X ray?
fi = 3.74 x 10^20 Hz
Deflected at 48°
Homework Equations
I'm...
Homework Statement
To confirm the wavelength of a new laser, a scientist prepares a diffraction grating with a distance of 5.00 x 10^-6 m between slits and places it in front of the laser which is 1.50 m in front of a screen. The scientist measures the distance from the central maxima to the...
Homework Statement
An electron (m= 9.11 x 10^-31 kg) enters a downward magnetic field of 5.00 x 10^-1 T with a velocity of 6.50 x 10^6 m/s West. Calculate the radius of the circular path it will follow when it is traveling within the magnetic field.
m = 9.11 x 10^-31 kg
v = 6.50 x 10^6...
Homework Statement
A particle has a charge of -5.00 \muC. At a point near this particle, the electric field strength is 7.2 x 10^7 N/C. Determine the distance from this point to the charged particle.
q = -5.00 x 10^-6 C
E = 7.2 x 10^7 N/C
k = 8.99 x 10^9 Nm^2/C^2
Homework Equations
E...
Homework Statement
What is the distance between two charges of -5.00 C each if the force of electrostatic repulsion acting on them is 4.00 x 10^3 N?
q1 = -5.00 C
q2 = -5.00 C
Fe = 4.00 x 10^3
k = 8.99 x 10^9 Nm^2/C^2
Homework Equations
Fe = kq1q2/r^2
The Attempt at a Solution...
Homework Statement
If a 30 g bullet is shot with a velocity of +300 m/s from a 7.5 kg gun, what is the recoil velocity of the gun?
m1 = 0.03 kg
v1 = 300 m/s
m2 = 7.5 kg
Velocity initial for both objects is 0.0 m/s
Homework Equations
(m1 + m2)(v) = (m1v1) + (m2v2)
The Attempt...
Homework Statement
A 0.160 kg ball attached to a light cord is swung in a vertical circle with a radius of 70.0 cm. At the top of the swing, the speed of the ball is 3.26 m/s. The center of the circle is 1.50 m above the floor.
Determine the magnitude of the tension in the cord when the...
The ratio of the output (useful work) to the input (total energy used)
I read that regardless of speed, both the slow and fast chairlifts have identical efficiency, but I don't understand this.
Homework Statement
The energy lost operating a low-speed chairlift is the same as the energy lost operating a high-speed lift of equal path length. What happens to the efficiency when you change from a low speed to a high speed chairlift?
Homework Equations
We know that high speed...
Homework Statement
Propose an explanation for the following fact. Include a description of the energy transfers that would take place when the lift starts and stops.
A fully loaded chairlift requires more energy to start then it does to maintain motion.
The Attempt at a Solution
I...
Energy Question! Please Help!
Homework Statement
A 170g hockey puck sliding at 25 m/s slows to a speed of 10 m/s in a distance of 7.5m. Determine the force of friction causing the puck to slow down.
m=170g
= 0.170kg
V1 = 25 m/s
V2= 10 m/s
d = 7.5 m/s
Homework Equations
Kinetic Energy =...