An electric slot car has a coil with 100 turns of wire. These loops have a current of 0.1 A and cover an area of 0.1 cm2. If the coil is placed in a uniform 1 T magnetic field such that the loop areas are perpendicular to the B-field, what torque will be felt by the coil?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)