Want to know the secret to the Force…

Youngling, younglings gather

round…Use equations you

must

KL physics2011

Equations we will use

�⃗�=𝑚�⃗�

𝜏= �⃗� 𝑟Torque

FAlso the idea that Net force = the sum of all of the forces acting on the object

Units to knowQuantity Symbol Unit

Force Newton (N)

Mass m Kilogram (kg)

Acceleration m/s2

Torque τ Newton meter (Nm)

Lever arm r Meter (m)

Example 1 – Finding Mass

What is the mass of a 650 N dog?

Example 2 – Finding Net Force

A rocket engine applies an upward force of 500 N to a small rocket. The rocket has a mass of 35 kg. Find the net force on the rocket.

Example 3 – Finding acceleration A rocket engine applies an upward force of 500 N to a small rocket. The

rocket has a mass of 35 kg. Find the acceleration of the rocket.

Whoa there Yoda…What’s TorqueNot every force moves in a straight line, think about using a wrench or opening a

door.

Torque is the effect of a force applied on an object that causes rotation.

Whoa there Yoda…What’s TorqueTorque is the effect of a force applied on an object that causes rotation.

Lever arm

rFulcrum – center of rotation

Lever arm – distance from fulcrum to the point the force is applied

Direction of rotation – clockwise (cw) or counter –clockwise (ccw)

Whoa there Yoda…What’s TorqueTorque is the effect of a force applied on an object that causes rotation.

Lever arm

r

Whoa there Yoda…What’s Torque

The amount of the force and the distance from the axis of rotation determine the torque.

𝜏= �⃗� 𝑟

Example 4 – Finding Torque

How much force will a technician need to tighten a bolt to 100 Nm if the longest wrench he can find is 0.2m long?

Use the force…

Armed you are now…Practice you must…

Prepare yourself young Jedi. Yes…you will be tested!