Physics-Forces
Newton's third law states that
Every action has an equal and opposite reaction
A 3-kg object is moving to the right at a constant velocity of 2 m/s. Which of the following horizontal forces is required to maintain this state of motion?
0 N.
Two objects gravitationally attract with a force of 18 N. If the distance between the two objects' centers decreased by a factor of three, then the new force of attraction is....
162 N
Two objects gravitationally attract with a force of 18 N. If the mass of BOTH of the objects are doubled and the distance between their centers is doubled, then the new force of attraction is....
18 N
Two objects gravitationally attract with a force of 18 N. If the distance between the two objects' centers is tripled, then the new force of attraction is.....
2 N
Two objects gravitationally attract with a force of 18N. If the distance is between the two objects' centers is doubled, then the new force of attraction is _________.
4.5 N
What is the force of gravity on a 60 kg student in orbit 60 miles above the Earth?
570 N
The force of gravity of objects on the moon is approximately one-sixth of their value on Earth. Joe weighs 600N on earth. Joe's mass on the moon would be...
60 kg.
Two objects gravitationally attract with a force of 18 N. If the distance between the two objects' centers is halved, then the new force of attraction is....
72 N
Two objects gravitationally attract with a force of 18 N. If the masses of one of the objects is doubled and the distance between their centers is doubled, then the new force of attraction is....
9 N
Action and reaction forces always occur in equal and opposite pairs. They do not balance each other because the....
Action and reaction forces act on different objects.
On which planet would you have the greatest mass?
All the same.
According to Newton's third law, if a fly splatter on the windshield of a fast-moving truck, which experiences the most force?
Both the same.
An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of two then the new acceleration would be 10 m/s/s.
FALSE, it would be 16 because DIRECT relationship.
An object has an acceleration of 8 m/s/s. If the mass of the object is increased by a factor of 2, then the new acceleration would be 16 m/s/s.
FALSE, it would be 4 because INVERSE relationship.
Inertia is a force...
FALSE.
Out on the playground, big Fred comes up to little Harry and gives him a shove. The reaction force to the force of Fred pushing on Harry is
Harry pushing Fred
In a careless moment, Jane miscalculates her footing and falls from a low branch on a tree, the reaction force to the force of the earth pulling Jane down is...
Jane pulling the earth up.
On which planet would you have the greatest weight?
Jupiter
What is the official metric unit for force?
Newton
In an Olympic boxing match, Ricardo delivers a sharp blow to Sonny's forehead. The reaction force to the force of Ricardo striking Sonny is...
Sonny applies a force to Ricardo.
A ball is thrown vertically upwards. After the ball is released and is moving upwards towards its peak, it slows down. During this time....
The ball is experiencing an unbalanced force; it is directed downwards.
A linebacker strikes a fullback with full force. The reaction force to the force of the linebacker striking the fullback is...
The fullback applies a force to the linebacker
Inertia
The tendency of an object to resist change.
Which famous astronomer discovered that planets move in ellipses?
Tycho Brahe
The force of gravity that acts upon an object is referred to as the.....
Weight
The force of gravitation between two objects is....
always an attractive force.
An object moving at a constant velocity MUST...
be experiencing a balance of forces
The law of inertia (Newton's first law) applies to...
both moving and nonmoving objects
Suppose that an astronaut throws a rock in outer space at a location far from significant influences of gravity and air resistance. One would expect that the rock would...
continue in motion with the same speed and direction.
The acceleration of an object is_______ proportional to the net force and ________ proportional to its mass.
directly, inversely
The Earth is held in orbit by the force of gravity between the Earth and the more massive sun. The force of the Earth on the sun is __________ the force of the Sun on the Earth; the resulting acceleration of the Earth is ________ the acceleration of the Sun.
equal to, greater than
Late one night, an unfortunate bug collides with the windshield of a fast-moving bus. The force of the bug is ______ the force of the bug on the bus; the resulting acceleration of the bug is________ the acceleration of the bus.
equal to, greater than.
A large truck rear-ends a less massive car at a stop sign. The force of the truck on the car is _______ the force of the car on the truck; the resulting acceleration of the truck is_______ the acceleration of the car.
equal to; less than
Mass is expressed in units of ________ and weight is expressed in units of _________
kilograms (kg), Newtons (N)
The amount of matter or stuff in an object is referred to as...
the mass of the object.
A carpenter is pounding a nail into a wall. The reaction force of a hammer hitting a nail is
the nail forcing the hammer.
A car makes a left-hand turn. The front seat passenger claims that she feels a sensation of being pulled outwards. This is best explained by the fact...
the passenger has a natural tendency to move tangent to and out of the circular path