physics revision

Question 1

what is friction?

Answer 1

the resistance that one surface or object encounters when moving over or through another material

Question 2

what is inertia?

Answer 2

the natural tendency of objects in rest to stay at rest, and in motion to stay at a constant motion unless acted on by an additional force

Question 3

what is the net force acting on an object?

Answer 3

the sum of all the forces

Question 4

inertia is directly related to an objects?

Answer 4

mass

Question 5

if a book is at rest on top of a table what is the net force?

Answer 5

0

Question 6

if a pencil case is slid along a desk it comes to a stop because?

Answer 6

friction is acting in the opposite direction to the motion

Question 7

if a firefighter slides down a vertical pole, in which direction does the force of friction act on the firefighter?

Answer 7

upwards

Question 8

what is newtons first law?

Answer 8

an object at rest remains at rest unless acted upon by a net force

Question 9

which law is best demonstrated when a spaceship cruises through space at a constant speed without using any fuel?

Answer 9

newton’s first law

Question 10

if a skateboard stop suddenly, the rider can fall forwards which is an example of what law?

Answer 10

first law

Question 11

according to the second law, the amount of force needed to move an object depends on how fast you want it to move (acceleration), as well as an object’s..?

Answer 11

mass

Question 12

when a certain net force is applied to one brick on a frictionless surface, it accelerates at 6 m/s2. when the same net force is applied to three bricks that are cemented together, how much would they accelerate at?

Answer 12

they accelerate at 2m/s2

Question 13

to accelerate a 6kg mass at 2m/s2 requires a net force of..?

Answer 13

12N

Question 14

if an alien on a planet with an acceleration of gravity equal to 20m/sec2, and the aliens mass is 10kg, how many N does the alien weigh?

Answer 14

200N

Question 15

a free body diagram illustrates the forces acting on a 2kg object as it is being pushed along a horizontal surface, in which direction is there a net force? (look at example)

Answer 15

right

Question 16

a free body diagram illustrates the forces acting on a 2kg object as it is being pushed along a horizontal surface, how fast is the object accelerating? (look at example)

Answer 16

3.1m/s2

Question 17

a falling object is said to reach terminal velocity when..?

Answer 17

its air resistance equals the force of gravity on it

Question 18

the law of action and reaction is demonstrated when..?

Answer 18

when a hammer’s force is returned by the nail, causing the hammer to bounce

Question 19

newton’s third law states:

Answer 19

that forces always occur in pairs

Question 20

which observation is best explained by newtons third law? when turning a corner, a passenger in a car is pushed against a door, a skater on a frictionless skating rink tosses her bag in one direction and she accelerates in the opposite reaction, the friction of a surface causes a sliding object to come to rest or when firing a rifle, the force of the rifle on the bullet is greater than the force of the bullet back on the rifle.

Answer 20

a skater on a frictionless skating rink, tosses her bag in one direction and she accelerates in the opposite direction.