Work and Energy
When holding a ball above your head are you doing work?
No, work has been done.
You are traveling 10mph in a small car, next to you a large SUV is traveling at 10mph. Which vehicle has more momentum?
The large SUV.
A simple pendulum with a mass of 2kg is oscillating with a period of 10s. What happens to the period if the mass is increased to 4kg?
The period will remain unchanged.
The primary function of a wave is to ____________?
Transfer energy.
What type of wave is a sound wave?
Longitudinal Wave
A weightlifter exerts 600N to bench press. He lifts the bar 45 cm above his chest and brings it back down to its starting position. How much work has been done?
No work has been done because the total displacement is zero.
Two objects of different mass are traveling at different speeds. The first object has a speed that is ⅓ the speed of the second object, however it is 3 times more massive than the second object. Which has a greater momentum?
They have the same momentum.
A mass on a spring of mass 5kg is oscillating with a period of 5s. The mass is doubled what happens to the period?
The period will increase.
A wave in which the disturbance is perpendicular to the direction of propagation is________________?
Transverse Wave
What is the range of human hearing?
20 Hz to 20,000 Hz
A box is lifted and placed on a shelf 4.5m high. The box gains 160 J of potential energy. How much mass does the box have?
PE=mgh
m=PE/gh
m=3.63 kg
A 3km asteroid is predicted to pass within 5km of Earth's atmosphere. The asteroid has a mass of 5.2x1013kg. It passes the earth with a speed of 50km/s. How much momentum does the asteroid have?
2.6x1018kgm/s
A pendulum oscillates with a period of 45s. What is the frequency?
0.02 Hz
A wave of wavelength 4m is traveling at 40m/s. The frequency of the wave doubles however the wavelength does not change. What is the speed of the wave?
80 m/s or doubles
A sound wave traveling in air at 20°C has a frequency of 4,000,000Hz. The sound wave enters stainless steel what is the wavelength of the resulting in the sound wave? (vair=343m/s, vss=5790m/s)
1.45x103m
KE=1/2mv2
v=sqrt(2KE/m)
v=11.5m/s
While standing on skates on a frozen pond, a student of mass 75.0 kg catches a 4.00 kg ball traveling horizontally at 12.0 m/s towards him. What is the students speed immediately after catching the ball?
0.61m/s
What is the length of a pendulum that oscillates with a period of 2 second?
0.99m
Wave speed is determined by the _____________.
wave medium
On a very cold day 0°C an train is traveling at 56m/s. As it approaches an intersection the conductor sounds the horn to alert drivers. The horn transmits the sound at a frequency of 500 Hz. What is the frequency heard of a person standing near the tracks as the train approaches? (vair=331m/s)
602 Hz
A rollercoaster has 15,000J of PE at the top of its ramp. How much KE does it have 3/4 of the way down the ramp?
KE=11,250J
Two objects are placed 4m apart. One object has a mass of 65kg while the other object has a mass of 90kg. What is the center of mass for the two objects?
2.3 m from the origin.
1.7 m could also be accepted.
By increasing the displacement of a mass on a spring we see that the frequency on the oscillations are unchanged. What does this tell us about the speed of the mass?
A wave is traveling with a frequency of 40 Hz. It is traveling with a velocity of 250m/s. What is the wavelength?
6.25 m
On a very cold day 0°C an train is traveling at 56m/s. As it approaches an intersection the conductor sounds the horn to alert drivers. The horn transmits the sound at a frequency of 500 Hz. What is the frequency heard of a person standing near the tracks as the train passes? (vair=331m/s)
428 Hz