The question is poorly written.
ALL of the choices cause a change in something.
A). Force causes a change in velocity.
B). and C). Power and energy cause changes requiring work.
D). Impulse causes a change in momentum.
Answer:
To produce magnetic field
Explanation:
When current passes through a coil in presence of magnetic field then torque is produced in it.This is the working principle of motor.
Answer:
the train stopped for 3 seconds
Explanation:
Answer:
0.1m/s²
Explanation:
Using the equation of motion
V = u+at
V is the final speed = 0.9m/s
Initial speed u = 0.5m/s
Time = 4secs
Get the acceleration
0.9 = 0 5+4a
0.9-0.5 = 4a
0.4 = 4a
a = 0.4/4
a = 0.1m/s²
Hence the acceleration is 0.1m/s²
