Answer should be the earth
Answer:
Friction, normal force, and weight
Explanation:
If the book slows down, it means that there must be friction acting in the opposite direction of the direction the book is moving in.
Weight is caused by the gravitational pull of the Earth on the book, and normal force is the table pushing the book up because the book is pushing down on the table (3rd law.)
Note that weight and normal force is not the 3rd law action-reaction pair. The pair is the force of the book on the table and the force of the table on the book.
Answer:
a) v = 6.43 m/s
b) v = 15.8 m/s
Explanation:
Speed of car = 56 km/h
56 km/h = 14.4 m/s
Angle rain makes on the glass to the vertical = 66°
Thus knowing that the opposite side of the angle is the distance moved by the car, and the adjacent side is the distance traveled by the rain in the same time
both of which are directly proportional to their velocities
Then
tan(66°) = 14.44m/s ÷ x
or x = 14.44/tan(66°)
Which is the vertical raindrop velocity of the relative to earth
v = 6.43 m/s vertically towards earth
For v relative to the car is we have vector sum of both velocities
v = √(14.44^2 + 6.43^2) = 15.8 m/s which is the velocity relative to car
= 15.8 m/s
Answer:
B) 4500 Pa
Explanation:
As pressure is force per unit area,
P = F/A
It stands to reason that the smallest pressure for a given force is when it is shared by the largest area.
The possible areas are
0.30(0.40) = 0.12 m²
0.30(0.50) = 0.15 m²
0.40(0.50) = 0.20 m²
The pressure when the face with the largest area (0.20 m²) is down is
P = 900 / 0.20 = 4500 N/m² or 4500 Pa
the other possible pressures would be
900/0.15 = 6000 Pa
900/0.12 = 7500 Pa
which are both larger than our solution.
The strong nuclear force holds the nucleus of an atom together.
Somehow, it overcomes the electrical force of repulsion between protons in the nucleus, which all have the same charge but still stay close together somehow. (b)
