Forces and motions Part Two

Question 1

What is the equation for momentum

Answer 1

Momentum = mass x velocity

Question 2

what is the principle for conservation of momentum

Answer 2

Momentum before= momentum after

Question 3

what factors effect Momentum

Answer 3

Mass and velocity

greater mass of an object and the greater it’s velocity the more momentum the object has

Question 4

what is the equation linking force, change in momentum, time

Answer 4

Force= Change in momentum/time

Question 5

what are features of a car that reduce injury

Answer 5

Crumple zones- Crumple on impact, increasing the time taken for the car to stop

seat belts- stretch slightly, increasing time taken for the wearer to stop. (reduces the force on the chest)

Air bags- slows you down gradually

Question 6

Exaplain how reducing the force effects the risk of injury

Answer 6

A larger force means a faster change of momentum

faster change in momentum the force will be very large and more likely to cause injury

slowing down people after a crash means a longer time taken to change momentum the smaller force ( lower risk of injury)

Question 7

what is the equation for moment

Answer 7

Moment= force x perpendicular distance

Question 8

what is the definition of the centre of gravity

Answer 8

of an object as the point through which the weight of a body acts

Question 9

Explain the change in force when it moves further away from a pivot

Answer 9

Force increases

As perpendicular distance form the pivot increases

moment clockwise increases
moment anticlockwise Increases

to maintain equilibrium

Question 10

Finish the sentence

greater distance from pivot

Answer 10

greater moment

Question 11

What is the principle of moments

Answer 11

Sum of moments clockwise= the sum of moments anticlockwise