Work and Mechanical Energy

Work and Mechanical Energy

PHYNAL

Multiple Choice

What is the frequency of a merry-go-round that goes around 8 times a second?

• 50.24 HZ

• 0.125 HZ

• 0.12 Hz

• 8 KHz

Multiple Choice

Rawan stretches a spring and induces 20.0 kJ of elastic potential energy stored when it is stretched out. If its spring constant is 100.0 N/m, how far did Lexi stretch the spring?

• 20 m

• 200 m

• 100 m

• 10 m

Multiple Choice

A force of 30 N stretches a spring 0.73 m from equilibrium. What is the force constant (spring constant) of the spring?

• 22 N/m

• 41 N/m

• 43 N/m

• 36 N/m

Multiple Choice

The angular frequency of a pendulum oscillating with a period of 2 secs, is:

• 6.28 Rd/sec

• 1.57 Rd/sec

• 3.14 Rd/sec

• 0.318 Rd/sec

Multiple Choice

The period of an oscillation of a horizontal elastic pendulum formed of a mass m=9Kg and a spring of stiffness k=100N/m.

• 2.9 Sec

• 1.9 Sec

• 1 Sec

• 3 Sec

Multiple Choice

The angular frequency of a spring-mass system of mass 100 g and stiffness K=10N/m is:

• 5 Rd/sec

• 10 Rd/sec

• 0.1 Rd/sec

• 1 Rd/sec

Multiple Choice

The period of motion of a spring-mass system oscillating under friction is called:

• Proper period

• Pseudo period

• driven period

• Semi period

Multiple Choice

In a spring mass-system , the stiffness of the spring is quadrupled (x4), how is the period of the oscillations affected?

• period remains unchanged

• Period is quadrupled

• Period is halved

• Period remains the same

Multiple Choice

In a spring mass-system , the mass is quadrupled (x4), how is the frequency of the oscillations affected?

• frequency remains unchanged

• frequency is halved

• frequency is quadrupled

• frequency remains the same

Multiple Choice

In a simple harmonic motion, the period of oscillations is called:

• Proper period

• Pseudo period

• Semi period

• Forced period

Multiple Choice

The pseudo period compared to proper period is:

• Smaller

• Larger

• Equal

• Independent

Multiple Choice

A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its kinetic energy is a maximum?

• at either A or B

• midway between A and B

• one-third of the way between A and B

• one-fourth of the way between A and B

Multiple Choice

The initial phase (φ) of an oscillator starting at x=0, with an initial speed v₀>0 is;

Note: x=x_msin(ωt+φ)

• φ=-π/2 Rd

• φ=π Rd

• φ=0 Rd

• φ=π/2 Rd

Multiple Choice

In a free damped oscillation, the Mechanical energy

• is conserved

• decreases

• increases

• reamains constant

Multiple Choice

In a Simple harmonic motion, the acceleration of motion is:

• proportional to x²

• Proportional to 1/x

• proportional to x

• Proportional to -x

Multiple Choice

GS only

A pendulum is 0.75 meters long and has a period of 4.17 seconds. The Pendulum is on an unknown planet. What is the gravity of the Unknown Planet? (in m/sec²)

• 9.8

• 3.4

• 1.7

• >9.8

Multiple Choice

GS-only

What is the period (in secs) of a simple pendulum which has a length of 40m (use g=10m/s²)?

• 4π

• 2

• 8π

• 4

Multiple Choice

GS-only

Two torsion wires of torsions constants C₁ and C₂, carry identical masses. Their periods of oscillations are related by: T₁=2T₂.

The relation between C₁ and C₂ is:

• C₂=4C₁

• C₂=C₁/4

• C₂=2C₁

• C₁=2C₂

Multiple Choice

GS-only

A torsion pendulum is formed of a wire of torsion constant "C", connect to a disc of mass 2kg and radius 1m, oscillates with a period of 2 secs. The torsion constant C is:

• C=0.1

• C=10

• C=0.01

• C=100

Multiple Choice

GS-only

Two identical torsion wires of torsions constants C₁ and C₂, carrying 2 disks of equal radii and masses m₁=2m₂. Their periods of oscillations are related by:

• T₁=2T₂

• T₁=T₂/2

• T₁=√2T₂

• T₁=T₂/√2