Science Quizzes
The amount of force needed to keep a 1 kg hockey puck at a constant speed of 4 m/s on frictionless ice is
0 N
What is the ideal mechanical advantage of a 2 pulley system (with 2 supporting strands of rope)?
2
The balloon shooting forward on the string and the 2 liter bottle water-rocket shooting up in the air, were both examples of
Newtons 3rd law
The statement "for every action, there is an equal but opposite reaction" is a statement of ____.
Newtons 3rd law
Without an unbalanced force acting on it, a moving object will:
keep a constant velocity
Inertia causes a moving object to:
keep moving
How can you find the ideal mechanical advantage of an inclined plane?
length divided by height
An inclined plane wrapped around a cylinder post is a ____
screw
Which of the following is NOT an example of a wheel and axle?
screw
Which of Newton's laws of motion states that an object at rest will remain at rest and an object in motion will stay in motion unless acted on by an unbalanced force?
1
Which machine efficiency is impossible?
102 percent
A cat pushes a 0.25-kg toy with a net force of 4N. According to Newton's second law, what is the acceleration of the ball in m/s2?
16
Pliers and scissors are both which class of lever?
1st
A girl uses 60 J of energy to move a box from the floor to a shelf. How much power does she use if it takes her 3 s to move the box?
20 W
A wheelbarrow is an example of which class of lever?
2nd
What is the ideal mechanical advantage of a screwdriver with a 24-mm radius handle and an 8-mm radius shaft.
3
You use a constant force of 30 N to push a recycling bin down your 10 m driveway. How much work do you do in Joules?
300 J
A student uses a simple machine to help lift a load. When 40 N of input force is applied to the machine, it is able to lift 160 N. What is the mechanical advantage of the machine?
4
If a net force of 24 N is applied on a 6 kg mass, what will be the acceleration of the object in m/s2?
4
With a pulley that lifts 100 kg with only 25 kg. of effort how much farther will I have to pull the rope, if there is no friction?
4
Calculate the momentum of a 16-kg bicycle traveling north at 3 m/s in kg.m/s north.
48
Consider two objects whose masses are 100 g and 200 g. The smaller object strikes the larger object with a force of 500 N. According to Newton's third law of motion, what force does the larger object exert on the smaller object
500 N
A dressmaker is cutting fabric. She applies 18J of work to the scissors. The scissors apply 15J of work to the fabric as it cuts. What is the efficiency of the scissors?
83%
A moving object collides with a stationary object. Which of the following statements is true according to Newton's third law of motion?
Each object exerts a force on the other, and the two forces are equal and in opposite directions.
Newton's 1st law of motion is called the law of:
Inertia
Which term describes the tendency of a moving object to continue moving at the same velocity unless an unbalanced force acts on it?
Inertia
According to Newton's third law, when one object exerts a force on a second object, the second object does what?
It exerts an equal force on the first object, in the opposite direction.
Air is forced from the bottom of a rocket and it lifts off. This force causing the rocket to lift off is the
Reaction force
Jessica has two balls. One ball has a mass of 1 kg. The other ball has a mass of 2 kg. She pushes each with a force of 100 N. How does the acceleration of the two balls compare?
The 1-kg ball accelerates twice as much as the 2-kg ball.
Examples of Newton's Third Law
The recoil of a gun, The motion of rockets, The flying of a bird
Which three units are used in the equation for power? (P=W/t)
Watts, Joules, Seconds
which does NOT describe a action-reaction force pair?
When you push on a bike's brakes, the friction between the tires and the road increases
How are work and power related?
Work is done by using energy, and power is the rate at which work is done. Work is force multiplied by displacement
If you are making/designing a race car, according to Newton's 2nd law, what are 2 things that you can do to make it accelerate faster? (be somewhat specific about how)
You would need more force and less mass. To make it have more force you would need to make a bigger engine and to make it have less mass you would need to make it lighter or take off unnecessary parts.
According to Newton's second law of motion, ____.
a=f/m
Which will be SMALLER, the work input or the work output?
work output
Which of the following would have the most momentum?
big truck, going fast
Machines change the way work is done. In what two ways can a machine accomplish this?
by changing the size or direction of force
Which is an example of a compound machine?
can opener
In order to get a LEVER to make your job easier (less effort), where should you put the pivot/fulcrum?
closer to the object
When two or more simple machines work together, they are called a/an: ____.
compound machine
In using simple machines, in order to make work easier (less effort), what do I have to do more of (what is the trade off)?
distance
Which of Newton's laws explains why the crash dummy goes forward when not wearing a seatbelt?
first
A winding mountain road is an example of a/an
inclined plane
A moving train car collides with another train car that is motionless on the track. The train cars are the same size. How does the final/total momentum of the two cars compare to the momentum of the first car?
it is the same
Identify the 2 most obvious simple machines in a pair of scissors.
lever and wedge
list 6 simple machines
lever, inclined plane, wedge, screw, pulley, wheel and axle
In order to have the least EFFORT force in turning a wheel & axle (making it easier), theHANDLE/crank should be the axle it is turning?
longer than
An object of large mass has _____ than an object of small mass.
more momentum
We put an index card with a penny on top on a cup, then flicked the card off the cup. Which law explains why the coin fell into the cup rather than moving with the card?
newtons first law of motion
A bottle opener is an example of a second-class lever.Which of the following statements is true about second-class levers?
the output force is between the input and fulcrum
Which is a simple machine?
tweezers