Physics Worksheet - Georgia State University printable pdf download

Physics Worksheet - Georgia State University

Chapter 20 (Answers are all A's)

1. Find the displacement of a simple harmonic wave of amplitude 6.44 m at t = 0.71 s.

-1

Assume that the wave number is 2.34 m

, the angular frequency is 2.88 rad/s, and that the

wave is propagating in the +x direction at x = 1.21 m.

A) 4.55 m B) 1.05 m C) 3.54 m D) 2.25 m

Formula: y = a sin(kx-ωt+φ

). Here, φ

= 0.

2. Find the speed of an ocean wave whose displacement is given by y = 3.7 cos(2.2x – 5.6t)

where x and y are in meters and t is in seconds.

A) 2.5 m/s B) 1.9 m/s C) 3.5 m/s D) 4.5 m/s

Formula: y = a cos(kx - ωt+ φ

) = a sin(kx- ωt + φ

), where φ

= φ

+π/2. Here φ

= 0.

3. Transverse waves propagate at 43.2 m/s in a string that is subjected to a tension of 60.5

N. If the string is 19.0 m long, what is its mass?

A) 0.616 kg B) 0.259 kg C) 0.437 kg D) 0.715 kg

Formula: v =

and µ = M/L.

4. The density of aluminum is 2700 kg/m3. If transverse waves propagate at 34 m/s in a 4.6

mm diameter aluminum wire, what is the tension on the wire?

A) 52 N B) 31 N C) 42 N D) 62 N

Formula: v =

, µ = ρA and A = πr

5. A 4.24 m long, 1.27 kg rope under a tension of 475 N oscillates with a frequency of 11.2

Hz. If the oscillation amplitude is 6.32 cm, how much energy is required to keep the rope

oscillating for 5.52 s?

A) 651 J B) 553 J C) 605 J D) 697 J

Formula derivation: differentiate y-displacement to derive the speed along y and, k.e. of a

small segment, then find the average power. Here is the formula for average power:

P =

and energy required = P∆t, where ∆t = 5.52s.

6. Light from a laser forms a 1.31 mm diameter spot on a wall. If the light intensity in the

spot is 3.69 × 104 W/m2, what is the power output of the laser?

A) 49.7 mW B) 30.8 mW C) 41.7 mW D) 57.7 mW Formula: P = IA, where A = πr

Physics Worksheet - Georgia State University