Answer:
Friction acts in the opposite direction to the motion of the truck and box.
Explanation:
Let's first review the problem.
A moving truck applies the brakes, and a box on it does not slip.
Now when the truck is applying brakes, only it itself is being slowed down. Since the box is slowing down with the truck, we can conclude that it is friction that slows it down.
The box in the question tries to maintains its velocity forward when the brakes are applied. We can think of this as the box exerting a positive force relative to the truck when the brakes are applied. When we imagine this, we can also figure out where the static friction will act to stop this positive force. Friction will act in the negative direction. Or in other words, friction will act in the opposite direction to the motion of the truck and box. This explains why the box slows down with the truck, as friction acts to stop its motion.
Explanation:
Here's a clearer rendering of the question requirements;
Complete the sentences with the correct wording. Imagine that a force gauge is mounted between the rope and the chain carousel saddle. If you do not touch your feet to the ground when the vehicle is stationary, the dynamometer indicates A / B. When the carousel turns, you will read C / D on the dynamometer.
A. Your weight with the saddle
C. Rope strength value
B. Your weight
D. Centripetal force value
Answer:
Testing
Explanation:
Ancient Greek philosophers lived with the ideology to simply contemplate life. This means that their whole life revolved around thinking and questioning everything. This would include creative thinking, because they would sometimes come up with theories which require creativeness. They would often debate with their friends as to why their theory should be accepted or what their opinions were on the matter. More often than not, they argued a lot, and many philosophers went against some powerful people in the community and some were even sentenced to death.
The main process they didn't/couldn't do was the testing. They could never test certain theories because they did not have the means to.
Answer with Explanation:
We are given that
Radius of solid core wire=r=2.28 mm=
Radius of each strand of thin wire=r'=0.456 mm=
Current density of each wire=
a.Area =
Where 
Using the formula
Cross section area of copper wire has solid core =
Current density =
Using the formula
Total number of strands=19
Area of strand wire=
b.Resistivity of copper wire=
Length of each wire =6.25 m
Resistance, R=
Using the formula
Resistance of solid core wire=
Resistance of strand wire=
Answer:
0.214 m
Explanation:
In order for the bag to levitate and not fall down, the electrostatic force between the bag and the balloon must balance the weight of the bag.
Therefore, we can write:
where
k is the Coulomb constant
is the charge on the balloon
is the charge on the bag
r is the separation betwen the bag and the balloon
is the mass of the bag
is the acceleration due to gravity
Solving for r, we find the distance at which the bag must be held:
