Forces

Question 1

What is the name given to the single force that is equivalent to all the other forces acting on a given object?

Answer 1

The resultant force

Question 2

State Newton’s first law for a stationary object.

Answer 2

If the resultant force on a stationary object is zero, the object will remain at rest

Question 3

State Newton’s first law for a moving object.

Answer 3

If the resultant force on a moving object is zero, the object will remain at constant velocity (same speed in same direction)

Question 4

State the defining equation for Newton’s second law.

Answer 4

Resultant force = Mass x Acceleration

F = ma

Question 5

State Newton’s second law in words.

Answer 5

An objects acceleration is directly proportional to the resultant force acting on it and inversely proportional to its mass

Question 6

What is weight?

Answer 6

The force that acts on an object due to gravity and the objects mass

Question 7

What quantities does weight depend on?

Answer 7

Weight = mass x gravitational field strength

• The objects mass
• The gravitational field strength at the given position in the field

Question 8

What is the unit used for weight?

Answer 8

The Newton (N)

Question 9

What is the unit used for gravitational field strength?

Answer 9

N/kg

Question 10

What piece of equipment can be used to measure an objects weight?

Answer 10

A calibrated spring-balance or newton-meter