Revision

If the mass of an object decreases to half, the weight …………………

• increases to the double

• decreases to the half

• not change

The objects full down by effect of ……………

• gravitational force

• magnetic force

• nuclear force

Friction causes a great loss of mechanical energy because this energy is

changed into ………………… energy

• Sound

• heat

• electric

• light

………………………… is technological application of inertia

• Cars' brakes

• Pulse inside blood vessel

• Safety belt

• electromagnet

if the mass of an object = 30 kg and the gravitional acceleration = 10 m/s2, so its weight = ................ N

• 30

• 3

• 3000

• 300

From the forces produced due to motion are ……………… and …………….

• inertia - friction

• inertial - nuclear

• friction - chemical

The combination between ammonia and hydrochloric acid form …………… of ammonium chloride.

• white ppt.

• white powder   

• white solution

From forces enable living organisms to do biological operation ……………

• pulse

•  Friction

• inertia force

Waves that don't need a medium to travel called ........

• mechanical

• electromagnetic

• sound

...........The property of an object to resist the change of its phase from rest to motion unless an external force acted upon it.      

• friction

• inertia

• force