A antimatter is particle physics, antimatter is a material composed of the antiparticle "partners" to the corresponding particles of ordinary matter. A particle and its antiparticle have the same mass as one another, but opposite electric charge and other quantum numbers.
Answer:

Explanation:
As we know that the angle of incidence is given as

also we have angle of refraction as

now by Snell's law we know that


now we have


Answer:
180 miles/hr
Explanation:
15 min=1/4 hr
s= distance/time
s=45miles/1/4 hr
s=45miles x 4/1=180 miles/hr
Answer:
2.47 m/s
Explanation:
Momentum = Mass X Velocity
If they were locked together, it means its a perfectly inelastic collision. Therefore,
Total momentum before = Total momentum after
Total momentum before = (20 X 20) - (18 X 17)
= 94
Total momentum after = 94
Y = Object speed after collision
94 = (20+18)Y
Y = 2.47368421 m/s