### Linear Motion

you can be at rest relative to Earth, but moving about 107,00 km/h relative to the sun

how can you be both at rest and also moving about 107,00o km/h at the same time

yes

speed = d/t

speed = d/t

you cover 10 meters in a time of 1 second. is your speed the same if you cover 20 meters in 2 seconds

instantaneous speed

does the speedometer of a car read instantaneous speed or average speed

distance covered = average speed x travel time

average speed= distance covered / travel time. do some algebra and multiply both sides ot this relation by travel time. what does the result say about distance covered

velocity – has both magnitude and direction

speed only has magnitude

speed only has magnitude

what is a vector quantity, speed or velocity? defend your answer

accelerator and brake

steering wheel

steering wheel

what two controls on a car cause a change in speed? what control causes only a change in velocity?

10 km/h/s

what is the acceleration of a car moving along a straight path that increases its speed from zero to 100 km/h in 10 s

2 km/h

4 km/h

10 km/h

4 km/h

10 km/h

by how much does the speed of a vehicle moving in a straight line change each second when t is accelerating at 2 km/h/s? at 4 km/h/s? at 10 km/h/s?

once for speed change and another for time change

why does the unit of time enter twice in the unit of acceleration

fall is free of air drag and forces other than gravity

what is the meaning of free fall

50 m/s

60 m/s

(g=10)

60 m/s

(g=10)

for a freely falling object dropped from rest what is the instantaneous speed at the end of the fifth second of fall?

10 at all time

how far will a freely falling fall from rest in five seconds? six seconds?

125 m

180 m

180 m

how far will an object move in one second if its average speed is 5 m/s?

5 m

how far will a freely falling object have fallen from a position of rest when its instantaneous speed is 10 m/s?

5 m

what does the slope of the curve on a distance-versus-time graph represent

speed

what does the slope of the curve on a velocity-versus-time graph represent

acceleration

does air resistance increase or decreases the acceleration of a falling object

decrease

what is the appropriate equation for how fast an object freely falls from a position of rest? for how far that object falls

v=gt

d= 1/2gt^2

d= 1/2gt^2

for a freely falling object dropped at rest, what is the acceleration at the end of the fifth second of fall? the sixth second? at the end of any elapsed time t?