A great, helpful, useful definition of acceleration is
<em>A = (change in speed) / (time for the change)</em> . <== you should memorize this
This simple tool will directly solve all 3 problems.
The REASON for assigning these problems for homework is NOT to find the answers. It's to help YOU find out whether you know this definition, to let you go back and review it if you don't, and to give you a chance to practice using it if you do. Noticed that if you get the answers from somebody else, you lose all of these benefits.
The only wrinkle anywhere here is in #3, because when you use this definition, the unit of time has to be the same in both the numerator and the denominator.
So for #3, you have to EITHER change the km/hr to km/sec, OR change the 4sec to a fraction of an hour, before you plug anything into the definition.
Answer:
A and C
Explanation:
drag (the area of lower air pressure behind the car when moving) and mostly air resistance (the work to push the air in front of us away to move through - the faster we go, the stronger the air resists to move aside).
Answer:
therefore critical angle c= 69.79°
Explanation:
Canola oil is less dense than water, so it floats over water.
Given 
which is higher than that of water
refractive index of water 
to calculate critical angle of light going from the oil into water
we know that

now putting values we get

c= 
c=69.79°
therefore critical angle c= 69.79°
<span>Like charges repel and opposite charges attract.
The further away two charged objects are the weaker the electrical force between them.
The closer two charged objects are the stronger the electrical force between them.
Hope this helps :)</span>
Answer:
resultant force = (f1²+f2²)½
=(1.5²+2²)½
=(2.25+4)½
=(6.25)½
=2.5
Explanation:
okay this question seems easy. now if the 1.5 is vertically upwards so is that 2 is horizontally downwards hence as u say its 90 degrees thn it forms a right angled triangle.