Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Explanation:
As the given data is as follows.
ohm
,
ohm,
= 1200
(as 1 k ohm = 1000 m)
(a) We will calculate the maximum resistance by combining the given resistances as follows.
Max. Resistance = 
=
ohm
= 2600 ohm
or, = 2.6
ohm
Therefore, the maximum resistance you can obtain by combining these is 2.6
ohm.
(b) Now, the minimum resistance is calculated as follows.
Min. Resistance = 
= 
=
ohm
Hence, we can conclude that minimum resistance you can obtain by combining these is
ohm.
Answer:
Velocity: +ve, Acceleration: -ve
Explanation:
Here I've considered downward direction as positive direction.