P10- Forces and motion

Question 1

what is resultant force?

Answer 1

when multiple forces act on an object, they can add together or subtract from each other until there is an equivalent of just one force acting in a single direction

Question 2

what does the size of an arrow show on a free body diagram?

Answer 2

relative magnitudes

Question 3

what does the direction of an arrow show on a free body diagram?

Answer 3

direction

Question 4

what is the equation for resultant force?

Answer 4

resultant force(N)= mass(kg) x acceleration(m/s^2)

Question 5

What is newton’s first law?

Answer 5

According to Newton’s first law of motion, an object remains in the same state of motion unless a resultant force acts on it. If the resultant force on an object is zero, this means:

:a stationary object stays stationary
:a moving object continues to move at the same velocity (at the same speed and in the same direction)

Question 6

What is Newton’s second law?

Answer 6

if a resultant force acts on an object it will accelerate. acceleration is proportional to the force. links to the equation for resultant force

Question 7

What is Newton’s Third Law?

Answer 7

for every equal action, there is an equal and opposite reaction.

Question 8

what is the equation for work done?

Answer 8

work done(j)= force(N) x distance(m)

Question 9

Required Practical: ACCELERATION

Answer 9

trolley has a piece of card which has a gap that will pass through the light gate and input this into the datalogger- ligth gate can measure velocity.
connect trolly to a piece fo string that goes over a pulley and is connected on the other side to a mass hanger.
weight of mass hanger and masses on it will provide the accelerating force equal to the mass of the hook x acceleration due to gravity(weight=mass x gravitaional field strength)
weight of mass hanger and masses accelerates both the trolley and masses, so you are investigating the acceleration of the system.
have a starting point of the trolley so it is always travelling at the same distance each time.
record the acceleration measure by the light gate as the trolley passes through it.
repeat twice to get average

Question 10

in the acceleration practical to investigate the effect of mass what do you do?

Answer 10

add masses to only the trolley and record the average for each mass
a=F/m (mass of system increases but force applied is the same)

Question 11

in the acceleration practical to investigate the effect of force what do you do?

Answer 11

need to keep total mass the same so start with all the masses on the mass hanger and then move them one by one to the trolley and record average acceleration
F=mxa (not changing the mass just an increase in force)

Question 12

Inertia

Answer 12

a measure of how difficult it is to change the velocity of an object
ratio of force over acceleration

Question 13

weight

Answer 13

force acting on an object due to gravity
measure in Newtons, N, vector quantity

Question 14

equation for weight

Answer 14

weight(N)= mass(kg) x gravitational field strength(N/kg)

Question 15

terminal velocity

Answer 15

the object moves at a steady speed in a constant direction because the resultant force acting on it is zero