P9&10- Force and Motion

Question 1

How do you calculate resultant force?

Answer 1

Resultant Force (N)= Mass(kg) x Acceleration(m/s)

Question 2

What are Scalar Quantities?

Answer 2

Only have magnitude or size (kg, m).

Question 3

What are Vector Quantities?

Answer 3

They have both magnitude and direction (km east).

Question 4

What is resultant force?

Answer 4

A single force that has the same effect as two or more forces.

Question 5

What does Newtons Second Law say about Acceleration?

Answer 5

Directly proportional to the resultant force of the object.

Inversly proportional to the mass of the object.

Question 6

What is Inertia?

Answer 6

The tendancy of an object to stay at rest or to continue it’s uniform motion. (Stop or continue going)

Question 7

What is the weight of an object?

Answer 7

The force acting on a object due to gravity measured in newtons.

Question 8

What is the mass of the object?

Answer 8

The quantity of matter in the object, measured in Kg.

Question 9

If the mass of a object is 1kg then what is the weight of it?

Answer 9

9.8 N (gravity)

Question 10

If the mass of an object is 5kg what is its weight?

Answer 10

50 N (5x10)

Question 11

What is the Equation of Weight?

Answer 11

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

Question 12

What is Terminal Velocity?

Answer 12

It’s the velocity a object finally reaches when falling, the weight of the of the object is equal to the frictional force on the object.

Question 13

What is the resultant force of an object when its at terminal velocity?

Answer 13

0 , as the force (friction and weight) are equal.

Question 14

What factors affect the braking force needed to stop?

Answer 14

The speed of the vehicle and mass of it.

Question 15

How do you find stopping distance?

Answer 15

Stopping distance = Thinking distance + Braking distance

Question 16

What is the thinking distance?

Answer 16

The distance travelled by the vehicle during in the time it takes the driver to react.

Question 17

What is the Breaking Distance?

Answer 17

The distance travelled by the vehicle during the time the braking force acts.

Question 18

Equation for thinking distance?

Answer 18

Distance= speed x reaction time

Question 19

4 factors affecting stopping distance are?

Answer 19

A

Question 20

What equation for breaking force?

Answer 20

B Force = Mass x Acceleration (same as resultant force)

Question 21

How do you calculate deacceleration?

Answer 21

A (deacceleration) = -U^2 (initial speed) / 2 x S (distance travelled)

Question 22

When is a object called elastic?

Answer 22

If it returns to is original shape after removing the force deforming it.

Question 23

What is extension?

Answer 23

The difference between the length of the object and its original length.

Question 24

What does it mean when a spring is beyond the limit of proportionality?

Answer 24

The extension of the spring is no longer proportional to the force applied to the spring.

Question 25

What does Hooke’s Law state?

Answer 25

The extension of a spring is directly proportional to the force applied, as long as its limit of proportionality is not exceeded.

Question 26

What is the equation for the extension of the spring?

Answer 26

Length at extension - original length

Question 27

What is Hooke’s Law Equation (spring constant)?

Answer 27

Force Applied = Spring Constant x Extension

Question 28

What is the Equation for Momentum?

Answer 28

Momentum (kg m/s) = mass (kg) x velocity (m/s)

Question 29

How do you find Inertial mass?

Answer 29

Force / Acceleration

Question 30

What is the general law of the Conservation of Momentum?

Answer 30

In a closed system, the total momentum before an event is equal to the total momentum after the event.

Question 31

What the centre of Mass?

Answer 31

The point of mass in which it is concentrated.