The measuring units of speed
m/sec
Km/h
The change of the object speed by equal values through equal periods of time
uniform acceleration
The change in the object's position as the time passes relative to the position of another fixed object
Motion
The physical quantity that has magnitude only and has no direction
Scalar quantity
The device used to measure the speed in cars and planes
speedometer
The total distance covered by a moving object divided by the total time needed to cover this distance
Average speed
The rate of change displacement
Velocity
A train covers 50 m in two seconds. Find the speed in Km/h
90 Km/h
What happens when the initial speed of a moving object is smaller that its final speed?
The object is moving with positive acceleration
(accelerating motion)
What's meant by:
A body moves with deceleration equals 2 m/sec2
This means that the body's speed decreases 2 m/sec every second
G.R.F.: The motion of the metro is considered a motion in one direction?
because it moves forward and backward and not upward and downward
G.R.F. The car moves at irregular speed?
Because it covers unequal distances in equal periods of time due to the traffic conditions
G.R.F. The relative speed of a moving car relative to an observer equals zero
Because the observer is moving in the same direction with the same speed
G.R.F.: The body which moves at acceleration can't move with a regular speed
Because the bogy moving with acceleration is changing its speed as the time passes
G.R.F. Pilots take into consideration the winds velocity?
To calculate the amount of fuel needed to complete the trip
A special car can move from rest and its speed reaches 90 m/sec in 10 seconds. what is the acceleration at which the car moved?
9 m/sec2
When do we say:
Distance covered by an object equals the displacement
when it moves in a straight line in one direction
When do we say:
The displacement equals zero
The body returns back to the staring point
When do we say:
Acceleration equals zero
When it moves at regular speed
When an object moves in a circular path covering a complete circle so the distance covered by this object is calculated as ------------
2 pi r