Answer:
B.The force of friction between the block and surface will decrease.
Explanation:
The force of friction is given by

where
is the coefficient of friction and
is the normal force.
When the student pulls on the block with force
at an angle
, the normal force on the block becomes

and hence the frictional force becomes
.
Now, as we increase
,
increases which as a result decreases the normal force
, which also means the frictional force decreases; Hence choice B stands true.
<em>P.S: Choice D is tempting but incorrect since the weight </em>
<em> is independent of the external forces on the block. </em>
Answer:
1.38*10^18 kg
Explanation:
According to the Newton's law of universal gravitation:

where:
G= Gravitational constant (6.674×10−11 N · (m/kg)2)
ma= mass of the astronaut
mp= mass of the planet

so:

Answer:
What is the best description for the volume of air volume of air provided in a high quality rescue breath?
Explanation:
A) only Enough air to create a visible rise of the chest.
B) Until you can no longer force air in.
C) plenty of air make sure it is adequate to sustain life
D) clear and obvious rise of the chest, sustained over a few seconds
They can have a close similar appearance to the parents, have close relation of child reactions.
for example, everyone born in my father's side of the family had the tendency to bump their head on something as they fall asleep up to the point when you are a toddler.