Question
calculate its size in meters per second squared.
click below
click below
Question
Normal Size Small Size show me how
speeding up revision
physics speeding up revision made from nzqa questions- ncea level1?
Question | Answer |
---|---|
In the first three seconds Mary’s acceleration is constant. Use the slope of the graph to calculate its size in meters per second squared. | Slope of graph gives acceleration. Hence: a = 30ms-1/3s = 10 ms-2 |
to find time you? | distance/speed |
to find speed you? | distance/time |
to find distance you? | time x speed |
Using Newton’s Second Law, explain why the sky diver must have no net force acting on her when she is falling at a constant velocity? | The net force on her is zero Newtons at her constant terminal velocity because she has no net acceleration. Hence by Newton’s second law, if anet = 0, then Fnet = m anet = 0 N. |
Mary has a mass of 65 kg. Calculate the size of the force of gravity acting on her as she falls. | F = mg = 65kg x 10 N/kg = 650 N |
terminal velocity | -drag and weight balanced -no accelerations; a=0 -at fastest possible speed -constant speed -zero change in speed, zero slope, zero acceleration -F=m,a. if a=0 f=0; weight less |
at slope= | ------- as constant acceleration |
vt slope= | acceleration/changing speed; no slope no acceleration= constant speed |
dt slope= | speed/velocity, more slope speed; no slope no acceleration = constant speed |