Answer:
(-y)-direction.
Explanation:
The force created by the magnetic field on a moving object is

So the directions are

The direction can also be found by the right-hand rule.
Point your index finger in the direction of velocity. Point your middle finger in the direction of magnetic field. Your thumb will point towards the direction of the force.
Answer:

Explanation:
Two identical sticky masses m are moving in the xy-plane, with their momenta at an angle of φ with one another. They are each moving at the same speed v when they collide at the origin of the coordinates and stick together. After the collision, the masses move at an angle −θ2 with respect to the +x axis at speed v2 .1. What was the angle φ?
from the principle of momentum
In a system of colliding bodies,we know that the total momentum before collision will equal to the total momentum after collision.
Take note that momentum is the product of mass and velocity
momentum before collision=momentum after collision
mass, m
u=initial velocity of the identical masses
v2=the common velocity after the collision
Note that the collision is inelastic , since they both moved with the same velocity
umcosφ+umcosφ=(m+m)v2cos−θ2
2mucosφ=2mv2cos−θ2

Increase in the amount of matter present...
All you need to know is that velocity is the derivative with respect to time of position.
Therefore: ds/dt = -32t +10
To know the velocity at t=2s you just need to plug t=2 for t in the equation above.
The most accurate answer among the choices would be the fourth one, because if the weight of the air displaced is greater than the balloon's weight, the balloon will float upwards. Density of the air also plays a part. Hot air = less dense. Hope my answer has come to your help.