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:
a,b,c,e,d
Explanation:
The typical approach by the scientists use to understand the physical world includes the following steps:
Identifying a Problem
Researching the Information
Stating a Hypothesis (Possible Solution)
Testing the Hypothesis
Gather Data
Analysis of the Data
Stating a Conclusion
Publishing the Result
Therefore, according to the question the correct order would be:
a. Observation of physical world.
b. Create hypothesis about observation.
c. Test consequences of hypothesis
e. Adjust results to agree with popular opinion
d. Report outcome
Answer:
Explanation:
The tip of the second hand moves on a circular path having radius equal to .22 m . Redial acceleration is given by the expression
ω²R where ω is angular velocity and R is radius of the circular path .
angular velocity of second hand = 2π / T where T is time period of circular motion . For second hand it is 60 s.
ω = 2π / T
= 2π / 60
= .1047
angular acceleration = .1047² x .22
= 2.41 x 10⁻³ rad / s² .
Answer:
The velocity is 
Explanation:
From the question we are told that
The mass of the ball is 
The radius is 
The force is 
The speed of the ball is 
Generally the kinetic energy at the top of the circle is mathematically represented as
=> 
=> 
Generally the work done by the force applied on the ball from the top to the bottom is mathematically represented as
Here d is the length of a semi - circular arc which is mathematically represented as
So
Generally the kinetic energy at the bottom is mathematically represented as
=> 
=> 
From the law of energy conservation
=> 
=>
Hello there.
<span>Electromagnetic radiation is:
</span><span>A- energy that is electric and magnetic
</span>
