Answer:
Speed is a scalar quantity it has only magnitude. So in the given scenario the student actually described about the velocity.
Explanation:
In this situation, student is describing that the speed is -10 m/s. The speed with the negative sign is wrong because speed is a scalar quantity and scalar quantities have only magnitude, they do not have direction. So, his statement is wrong because he is describing the speed with the negative sign.
And also we know that velocity is a vector quantity, so it has magnitude as well as direction also. So in this situation, the student is actually want to describe the velocity because he is mentioning the magnitude in a particular direction.
Answer:
<h2>117.6 J</h2>
Explanation:
The gravitational potential energy of a body can be found by using the formula
GPE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 9.8 m/s²
From the question we have
GPE = 6 × 9.8 × 2
We have the final answer as
<h3>117.6 J</h3>
Hope this helps you
Complete Question
The complete question is shown on the first uploaded image
Answer:
Explanation:
From the question we are told
The amplitude of the lateral force is 
The frequency is 
The mass of the bridge per unit length is 
The length of the central span is 
The oscillation amplitude of the section considered at the time considered is 
The time taken for the undriven oscillation to decay to
of its original value is t = 6T
Generally the mass of the section considered is mathematically represented as

=> 
=> 
Generally the oscillation amplitude of the section after a time period t is mathematically represented as

Here b is the damping constant and the
is the amplitude of the section when it was undriven
So from the question

=> 
=> 
=> 
=> 
Generally the amplitude of the section considered is mathematically represented as

=> 
=> 
=> 
=> 
Answer:
0.09 m/s²
Explanation:
Acceleration: This can be defined as the rate of change of velocity.
The S.I unit of acceleration is m/s².
From the question, expression for acceleration is given as
F' = ma
Using Pythagoras Theory,
√(F₁²+F₂²) = ma................... Equation 1
Where F₁ = Force of the First person on the boulder, F₂ = Force of the Second person on the boulder, F' = resultant force acting on the boulder, m = mass of the boulder, a = acceleration of the boulder.
make a the subject of the equation
a = √(F₁²+F₂²) /m................ Equation 2
Given: m = 825 kg, F₁ = 64 N, F₂ = 38 N,
Substitute into equation 2
a = [√(64²+38²)]/825
a = {√(5540)}/825
a = 74.43/825
a = 0.09 m/s²
Total number of Photons = 92.
Radius of the Nucleus = 7.4 x 10^-15 m
Charge of the nucleus = 1.6*10^-19.
Total charge q = 92 x 1.6*10^-19 = 147.2 x 10^-19
k = 9 x 10^9 N m^2 / C^2
Electric field charge E = kq / r^2
=> E = (9 x 10^9 x 147.2 x 10^-19) / (7.4 x 10^-15) ^2
=> (1324.8 x 10^-10) / 54.76 x 10^-30 => 24.19 x 10^20 N/C