C.half the energy is carried by the electric field and half is carried by the magnetic field.
Answer:

Explanation:
Let say the empty wagon has mass "M"
now by newton's II Law we will have

now it is given that empty wagon is pulled with acceleration 1.4 m/s/s
now we will have

now a child of mass three times the mass of wagon is sitting on the empty wagon
so here we have


so we have

(Mass does not affect the pendulum's swing. The longer the length of string, the farther the pendulum falls; and therefore, the longer the period, or back and forth swing of the pendulum. The greater the amplitude, or angle, the farther the pendulum falls; and therefore, the longer the period.)
Answer:12.28m/s
Explanation:
momentum of baseball =mass of baseball x velocity of baseball
Momentum of baseball =0.31x21
Momentum of baseball =6.51kgm/s
For a softball to have same momentum with the baseball we can say :momentum of baseball =mass of softball x velocity of softball
6.51=0.53 x velocity of softball
Velocity of softball =6.51/0.53
Velocity of softball =12.28m/s