Questions and Answers 8



If an object has kinetic energy, then it also must have
A) momentum
B) potential energy
C)chemical energy
D) speed

How fast does an object fall in feet per second
A) 10 feet per seconds
B) 32 feet per seconds
C) 22 feet per second
D) none of the above

If you do work on an object in half the time, your power output is
A) half original value
B) double
C) triple
D) none of the above

If the speed of a moving object doubles, which of the following also doubles?
A) velocity
B) kinetic energy
C) moment
D) potential energy

If the velocity of a moving object doubles, then what else doubles?
A) velocity
B) kinetic energy
C) moment
D) potential energy

A dog and a mouse run along a road with the same kinetic energy. The faster runner is the
 the faster runner is the mouse, for a dog and a mouse to have same kinetic energy , the mouse must move faster than the dog, a kinetic energy is directly related to the mass and speed of an object, if the dog with greater mass will have same k.e with a mouse then the mouse must move at greater speed.

An object at rest may also have?
A) velocity
B) kinetic energy
C) moment
D) potential energy

When the speed of a moving car is doubled, how much more kinetic energy does it have?
A) double
B) triple
C) halfed
D) remain the same

Which of these forms of energy is not renewable?
A) potential energy
B) hydro power
C) wind
D) nuclear


A 2-kg ball is held 4m above the ground. Relative to the ground its potential energy is?
A) 8j
B)80j
C)800j
D) 2j

A cat and a mouse run down the hallway with the same ke. The faster moving one is the?
  the faster is the mouse, kinetic energy is a product of squared veleocity and objet mass, for mouse to have same kinetic energy with

When an increase in speed doubles the momentum of a moving body, its kinetic energy
A) also doubled
B) remain unchanged
C)reduced to half
D) none of the above

When a hybrid car brakes to a stop, much of its kinetic energy is transformed to
A) potential
B) chemical energy
C) heat energy
D) friction


If an object has kinetic energy, it must also have
A) potential
B) chemical energy
C) heat energy
D) friction

When both the force and time of contact are doubled, the impulse on an object is?
A) doubled
B) halfed
C) unchanged
D) tripled


The impulse-momentum relationship is a direct result of newton's
A) 1st law of motion
B) 2nd law of motion
C) third law of motion
D) none of the above

What kind of energy does a person experience most during skydiving?
A) kinetic
B) potential
C) chemical
D) none of the above

If the mass of an object decreases to half, and its speed doubles, its momentum
A) also doubles
B) reduce to half
C) tripled
D) remain the same

Whereas impulse involves force and time, work involves force and
A) speed
B) distance
C) displacement
D) none of the above

If an object has momentum, it must also have
A) speed
B) kinetic energy
C) momentum
D) speed

Do heavier objects fall faster than lighter objects experiment
Both heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s

Why do objects fall at the same rate
Both heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s


Two objects dropped from the same height
Both heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s

Why do objects fall at the same rate in a vacuum
Both heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s

If two objects of different mass are dropped from the same height what happens?
Both the  heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s

What slows down a lighter object?
A) gravity
B) friction
C) viscosity
D) air resistance
E) upthrust

How fast do objects fall in kmph
A) 2.77kmph
B) 3kmph
C)10kmph
D)10mph

If a charging rhinoceros has momentum, it must also have
A)potential energy
B) kinetic energy
C) velocity
D) none of the above

The bob of a simple pendulum has its maximum kinetic energy at the
A) at the start
B) midddle
C) at the end
D) just before the end
E) just after starting

A heavy object and a light object are released from rest at the same height
Both heavy and light object fall at same rate in the absent of air resistance at a rate of 10m/s


When a hybrid car brakes to a stop, much of its kinetic energy is transformed to
A) chemical energy
B) potential energy
C) statistical energy
D) none of the above

An object has gravitational potential energy due to its
A) gravity
B) mass
C) weight
D) b and c

About 40 j is required to push a crate 4 m across a floor, what force used?
A) 10n
B) 30n
C)160n
D)44n

Can a machine multiply input force? Input distance? Input energy?
Answer this question

When two vehicles collide, momentum is conserved in  _______.
A) elastic collision
B) inelastic collision
C) scattering
D) fusion

When a drawn bow of potential energy 40 j is fired, the arrow will ideally have a kinetic energy
A) 40j
B) 400j
C)20
D) none of the above

If a machine multiplies force by a factor of 4, what other quantity is diminished, and by how much?
Answer this question
Recycled energy is mainly

The power expended doing 100 j of work in 50 s is?
A) 5000watt
B) 0.5 watt
C) 2 watt
D) 10 watts


Which energy production method does not ultimately depend on the sun?
A) nuclear
B) nuclear
C) hydro
D) fossil



What is the gain of potential energy of the barbell when it is lifted to this height xm ?

 the gain in the potential energy will be the weight of the barbel multiplied by the given height  xm.
For example if the barbel is 120 newton, the p.e will be 120newton * xm.



An object lifted 10 meters gains 200 j of potential energy, the object mass is ?

A) 40kg
B) 20kg
C) 2000kg
D)10kg



Calculate the power expended when a 500 n barbell is lifted 2.2 m in 2s
A) 250watts
B) 550watt
C) 1100 watts
D)2200

When joshua brakes his speeding bicycle to a stop, kinetic energy is transformed to
A) potential energy
B) tension
C) friction
D) heat energy

Which requires the most amount of work by the brakes of a car?
A) potential energy
B) tension
C) friction
D) heat energy

When is the potential energy of something significant?
A) when speed is zero
B) when in motion
C) when kinetic energy is maximum
D) when object not static




Fossil fuels, hydroelectric power, and wind power ultimately get their energy from _______.
A) power stations
B) earth
C) sun
D) none of the above





A ball rolling down an incline has its maximum potential energy at
A) at the top
B) middle
C) just before landing
D) just after starting

In what sense is energy from coal actually solar energy?

 coal is a rock formed from carbonized plant matter, found mainly in underground deposits over time, we know how plant use sunlight energy  to make their own food (photosynthesis),
 it is this same energy that is derived when coal is heated.
 therefore coal is also solar.

What is the source of energy in sunshine
A) fusion
B) fission
C) radioactivity
D) none of the above





How does speed affect the friction between a road and a skidding tire
Answer this question


Calculate the work done when a 20 n force pushes a cart 3.5 m
A) 70
B) 5.71
C) 20
D) 3.5

What will be the kinetic energy of an arrow having a potential energy of 50ja)
A) 50j
B) 5j
C) 500j
D) none of the above


Cite an example where a force is exerted
Answer this question
Calculate the kinetic energy of a 3 kg toy cart that moves at 4 m/s
A) 12j
B) 24j
C) 1.33j
D) 48j

Calculate the change in potential energy of 8 million kg of water dropping 50 m over niagara falls
A) 4billion joules
B) 400million joules
C) 160000 joules
D) 50joules

Calculate the work needed to lift a 90 n  4m up
A) 900n
B)360n
C) 3600n
D)22.5n

Calculate the power expended when a 20 n force pushes a cart 3.5 m in a time of 0.5 s
A) 70watts
B) 140watt
C) 10watts
D) 35 watts

Calculate the increase in potential energy when a 20kg block is up by 4m?
A) 80j
B)800j
C)5j
D) 4j



In which type of lever is the output force smaller
A) 1st order
B) 2nd order
C) 3rd order
D) 4th order

Calculate the work done when a 20 n force pushes a cart 3.5 m
A)70j
B) 5.71
C) 700
D) 200j

When one does twice the work in twice the time, the power expended is _______.
Answer this question



If a machine multiplies force by a factor of 4, what other quantity is diminished, and by how much?
Answer this question

If the force of friction on the crate is a steady 70 n, find the ke gained by the crate.
Answer this question

Can a machine multiply input force? Input distance? Input energy?
Yes or no

The work done in pushing a tv set a distance of 2 m with an average force of 20 n is
A) 40j
B) 2400j
C) 120j
D) 1200j


What does it mean to say that in any system the total energy score stays the same
Potential energy must be equal to kinetic energy, or system the mechanical energy of a system is equal to  constant ,

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