DD6

Which of the following are scalar quantities

• Energy

• Displacement

• Electrical resistance

• Force

Which of the following are vector quantities

• Work

• Current

• Velocity

• Acceleration

A car has travelled 6 Km East, followed by 3 Km east in 2 mins.

Calculate the cars speed and velocity.

A car reached a speed of 60 Km/S from rest in 2 mins. Its acceleration is

• 1 Km/S²

• 2 Km/S²

• 0.5 Km/S²

• 0.5 Km/S

Force is defined as

(a)  

Contact force

• is measured in Joules

• occurs between objects in physical contact

• such as gravity

• occurs between objects not in physical contact

Distance force

• Measured in Newtons

• occurs between objects in physical contact

• Such as friction

• Occurs between objects not in physical contact

Power

• is measured in Newtons

• is the rate of work

• is the product of force and velocity

• is the product of force and displacement

Newtons first law states that

• a moving object can randomly change speed

• acceleration is dependent on the force

• for every action there is a reaction

• A stationary object will only move if a force acts on it

Newtons second law states that

• Acceleration is independent on the force applied

• Acceleration is directly proportional to mass

• Acceleration is inversely proportional to mass

• Acceleration is dependent on the force applied