Answer:
1977.696 J
Explanation:
Given;
Weight of the box = 28.0 kg
Force applied by the boy = 230 N
angle between the horizontal and the force = 35°
Therefore,
the horizontal component of the force = 230 × cosθ
= 230 × cos 35°
= 188.405 N
Coefficient of kinetic friction, μ = 0.24
Force by friction, f = μN
here,
N = Normal force = Mass × acceleration due to gravity
or
N = 28 × 9.81 = 274.68 N
therefore,
f = 0.24 × 274.68
or
f = 65.9232 N
Now,
work done by the boy, W₁ = 188.405 N × Displacement
= 188.405 N × 30
= 5652.15 J
and,
the
work done by the friction, W₂ = - 65.9232 N × Displacement
= - 65.9232 N × 30 m
= - 1977.696 J
[ since the friction force acts opposite to the direction of motion, therefore the workdone will be negative]
Answer:
The smallest distance the student that the student could be possibly be from the starting point is 6.5 meters.
Explanation:
For 2 quantities A and B represented as
and 
The sum is represented as
For the the values given to us the sum is calculated as

Now the since the uncertainity inthe sum is 
The closest possible distance at which the student can be is obtained by taking the negative sign in the uncertainity
Thus closest distance equals
meters
Answer:
K.E = 4800 Joules.
Explanation:
Given the following data;
Mass = 600 kg
Velocity = 4 m/s
To find the kinetic energy;
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;

Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Substituting into the equation, we have;

K.E = 4800 Joules.
The best choice would be C. Keep one end of the rope tied to the post and have all six boys tug on the other end.
Reason:
A is not correct since in the first case which is B, untying the rope from the post and have 3 boys on each end of it tug, will provide equal or a near equal amount of tension since the boys are all within the same strength, however there can be variables that will affect the tension.
That means B would be true according to A, and then for C, having all six boys pull on the other end of the rope would provide greater tension, since if 3 boys of the same strength range can't break the rope when its tied to the fence, we add the other 3 boys of the same strength.
However, if 3 boys are on each end of the rope and of the same strength then the rope will not break since there is an equal amount of net force exerted on the rope.
We know that the fence can withstand the strength of 3 boys but if we add the other 3 boys then it could provide us with a different outcome.
3B < F
3B(2) ≥ F
So, therefore, our best choice would be C since A and B is incorrect.
With the below stated fact I think that the pros of using synthetic materials outweighs the cons.
Before we answer the question
If the pros of using synthetic materials outweigh the cons or otherwise, let us first establish the what a synthetic material is and its pros and cons
Synthetic material
Synthetic material is a material in which a substances are changed chemically to produce a material with different characteristics.
Types of Synthetic material
- Plastic bag
- Synthetic fiber/cloth
- Artificial sweetener
- Synthetic fuel
- Aspirin
Pros of Synthetic materials
- They are used in construction because of there strong bonding
- They can be molded
- They can be colored into any shade
- They are cheap
Cons of Synthetic materials
- Sometimes none degradable
- They do not absorb water.
- They are highly flammable
- Melts easily
In conclusion
Although Synthetic materials has so very pressing disadvantages to human kind it is unrefusable the importance of Synthetic materials to the day to day live of all humans
Therefore, I think that the pros of using synthetic materials outweighs the cons
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