Explanation:
Given that,
(a) Work done by the electric field is 12 J on a 0.0001 C of charge. The electric potential is defined as the work done per unit charged particles. It is given by :



(b) Similarly, same electric field does 24 J of work on a 0.0002-C charge. The electric potential difference is given by :



Therefore, this is the required solution.
Answer:
Catapult on the ground: Normal, gravity
Catapult (I'm assuming launching marshmallow): Reaction of Force Applied
Marshmallow: Force Applied
Explanation:
This is the forces that act on a stationary object and a launched object. The catapult may also experience a force friction if your teacher is taking a more practical sense.
Elastic
Explanation is that it is force which is snapping back
Answer:
1.93 x 10∧3 N
Explanation:
The picture attached shows the calculation