Answer:
In physics, the concept of a frame of reference is used to specify the perspective from which an object or event is observed.
A frame of reference is where the measurements or observations will be made. Because of this, observing an event may be different when changing from one frame of reference to another, because the measurements will be different.
Defining frames of reference is necessary because the movement is relative, it may be that from our perspective or from a frame of reference on earth we are at rest, but seen from a frame of reference in space, we are in motion due that the earth is always moving.
Another example of frames of reference is a moving plane. Seen from the ground an object in the plane moves at the speed at which the plane travels, but if the frame of reference is fixed on the plane, the object is at rest.
Answer:
c. V = k Q1 * Q2 / R1 potential energy of Q1 and Q2 separated by R
V2 / V1 = (R1 / R2) = 1/4
V2 = V1 / 4
Answer:
C. When the temperature of the liquid is the same throughout
Explanation:
The first rule of vectors is that the horizontal and vertical components are separate. Disregarding air resistance, the only thing we have to worry about is gravity.
The appropriate suvat to use for the vertical component is v = u +at
I will take a to be -9.81, you may have to change it to be 10 if your qualification likes g to be 10.
v = 30 + (-9.81x2)
v = 30 - 19.62
=10.38m/s
Therefore we know that after 2.0 s the vertical component will be 10.38ms^-1, ie 10m/s as the answers given are all to 2sf.
The horizontal component is completely separate to the vertical component and since there is no air resistance, it will remain constant throughout the projectiles trajectory. Therefore it will remain at 40ms^-1.
Combining this together we get:
(1) vx=40m/s and vy=10m/s