Forces and Newton's Laws

Question 1

In Physics howis speed measured?

Answer 1

metres per second (m/s)

Question 2

What is the equation for speed?

Answer 2

SPEED = DISTANCE
—————
TIME

Question 3

how do you calculate RESULTANT FORCE?

Answer 3

add all the forces acting tin the same direction and subtract all the forces acting in the opposite direction

Question 4

What is Newton’s First Law?

Answer 4

If the forces on an object are balanced then the object will remain at rest or travel at a constant speed in a straight line.

Question 5

Anastronaut in deep space has no forces acting on her.Describe her possible motion.

Answer 5

She could be stationary.
Or moving at a steady speed.

Question 6

What happens objects if the resultant force on the object is not zero?

Answer 6

a resultant force on an object will cause it to accelerate.

Question 7

what will a forward resultant force cause an object to do?

Answer 7

To speed up

Question 8

What will a backwards resultant force cause an object to do?

Answer 8

to slow down.

Question 9

What is acceleration measured in?

Answer 9

m/s2

Question 10

What is Newton’s second law?

Answer 10

Describes what happens to objects when there is a resultant force. The larger the resultant force the larger the acceleration.

Question 11

If the resultsnt force acting on an object doubles then the acceleration doubles. What is this reationship called?

Answer 11

Direct proportionality

Question 12

What happens if the mass of an object increases?

Answer 12

The acceleration gets less.

Question 13

What is the equation for Newton’s 2nd law?

Answer 13

Resultant Force = Mass x Acceleration
RF = M x a

Question 14

In Newton’s Second Law, the mass in the equation must be measured in ?

Answer 14

Kilos

Question 15

In Newton’s Second Law, the mass in the equation must be measured in ?

Answer 15

Kilos

Question 16

What doe Gravity do?

Answer 16

Causes objects to accelerate or fall towards the centre of the planet.

Question 17

The strength of gravity depends on 2 factors. What are they?

Answer 17

• the mass of an object (the more massive the planet the stronger the pull of gravity will be
• the distance from the object (the further away an object is from the planet the weaker gravity will be

Question 18

Gravity acts on objects to produce a force called?

Answer 18

Weight

Question 19

How is the WEIGHT of an object measured?

Answer 19

w = mg
w is the weight of the object in NEWTONS
m is the mass of the object in kilograms
g is the strength of gravity in m/s2 or N/kg

Question 20

If an object is near Earth’s surface we can take the strength of gravity to be ?

Answer 20

10 m/s 2