Answer:
Magnitude of the force is 2601.9 N
Explanation:
m = 450 kg
coefficient of static friction μs = 0.73
coefficient of kinetic friction is μk = 0.59
The force required to start crate moving is 
.
but once crate starts moving the force of friction is reduced .
Hence to keep crate moving at constant velocity we have to reduce the force pushing crate ie .
Then the above pushing force will equal the frictional force due to kinetic friction and constant velocity is possible as forces are balanced.
Magnitude of the force
<span>c. atoms are always in motion..............</span>
Answer:
Magnetism is the force exerted by magnets when they attract or repel each other.
Answer:
C. A rubber rod and a glass rod charged this way have opposite charges on them.
Explanation:
When a rubber rod is rubbed against cat fur, it acquires a negative charge, it becomes negatively charged.
When you then try to bring two rubber rod's together, they repel because like charges repel.
Meanwhile, when you rub a glass rod against silk, it loses electrons to the silk material and becomes positively charged.
When you bring two positively charged glass rod's together, they repel, because like charges repel.
However, when you bring the rubber rod and a glass rod together, the attract each other because unlike/opposite charges attract.
