Answer: D
Explanation: Force can do everything else.
An electric motor is an electrical machine that converts electrical energy into mechanical energy.
Electric motors work on the principal of the interaction between magnetic field electr-magnetism. A loop which is carrying the current is placed in a magnetic field. The loop will experience a torque. The torque starts rotating the coil and the propellers start to rotate when the current passes through the loop.
Answer:
time of collision is
t = 0.395 s

so they will collide at height of 5.63 m from ground
Explanation:
initial speed of the ball when it is dropped down is

similarly initial speed of the object which is projected by spring is given as

now relative velocity of object with respect to ball

now since we know that both are moving under gravity so their relative acceleration is ZERO and the relative distance between them is 6.4 m



Now the height attained by the object in the same time is given as



so they will collide at height of 5.63 m from ground