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Worksheets3. Acoustics- lesson 3 - Force and friction
Total questions: 27
Worksheet time: 14mins
What does Newton's First lae state?
Force equals mass times velocity
For every action, there is an opposite reaction
An object remains at rest or moves at constant speed unless acted on by a force
Energy is conserved in closed systems
Inertia is
A type of friction
Resistance due to heat
The tendency of an object to maintain its motion
The rate of change of velocity
Which of the following is the correct SI unit of force?
Erg
Newton
Dyne
Watt
What is the formula for force?
F = m * a
F = m / v
F = a / m
F = v * t
Friction is best described as
A form of kinetic energy
A type of mass
A force that oppose motion
A scalar quantity
What happens if net force = 0?
Object must move
Acceleration increases
Motion stays unchanged
Velocity becomes zero
A 2 kg object is accelerating at 3 m/s2. What is the force?
6 m
6 N
1.5 N
3.5 kg
What is the unit of force in CGS system?
Joule
Newton
Dyne
Erg
Which factor increases friction?
Surface roughness
Smoother surfaces
Lower velocity
Lower density
A body resists changes to its motion because of
Inertia
Gravity
Energy
Friction
Which situation represents balanced force?
A kicked ball
An object falling
A car accelerating
A box pushed from both sides with equal force
If velocity = 10 m/s, time = 2s, mass = 3kg. What is force?
10 N
15 N
6 N
5 N
What does 'net force' mean?
Friction only
Weight difference
Speed * time
The total effect of all acting forces
Which is a correct formula for frictional force (Ff)?
Ff = m*v
Ff = a / R
Ff = R * v
Ff = R / v
In a VNG test, eye movement changes abruptly due to a sudden head turn. What physical principle applies?
Energy conversion
External force causes acceleration
Only gravity applies
Thermal conduction
Tympanic membrane vibration in response to sound pressure is an example of
force acting on flexible surface
Newton's third law
Friction increasing pressure
scalar resistance
A patient wears a hearing aid that vibrates slightly during walking. What can reduce unwanted feedback?
Increase gain
Improve friction/resistance in design
Add battery
Reduce force
Two equal forces 10 N each, push a ear mold in opposite directions. What's net force?
0 N
20 N
10 N right
5 N left
A probe is pushed with 5 N right and 2 N left. Net force is?
3 N Left
3 N right
7 N right
10 N
What happens when two rough materials rub at high speed?
Friction increases due to heat
Friction drops
Net force = 0
Acceleration disappears
In a head impulse test, if acceleration is reduced, what happens to force (assuming mass is constant)?
Force increases
Force decreases
Force stays the same
Mass changes
If a balance test sensor detects force = 0, but motion still continues, what is the explanation?
Velocity become infinite
Inertia maintains motion
Force was miscalculated
The system failed
If force is calculated as F = m * v/t, what does this formula imply?
it ignores acceleration
It uses velocity change over time
it only applies to rest
It's used only in CGS system
How many dynes equal 1 N?
100 dyens
1000 dyens
100,000 dyens
1,000,000 dyens
What is the net force on stationary object with two equal 5 N forces acting in opposite directions?
10 N
5 N
1 N
0 N
Friction converts part of mechanical energy into
Sound
Inertia
Motion
Heat
In hearing aid tubing, which effect is likely caused by increased friction?
Increased sound intensity
Energy loss => decreased efficiency
Higher mass
Reduced resistance
