In which situation is no work being done? A. a person carrying a box from one place to another B. a person picking up a box from
2 answers:
Answer:
A person carrying a box from one place to another.
Explanation:
The work done is defined as the product of force, displacement and the angle between the force and displacement. Mathematically, it can be written as :
Where
is the angle between the force and the displacement
When , then W = 0 (since, cos 90 = 0)
The situation in which no work being done is (a) " a person carrying a box from one place to another". In this case, the force acting on the person is gravitational force only which acts in downward direction and the person is carrying box from one place to another. So, the angle between the force and displacement is 90 degrees. Hence, no work being done.
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Answer:
Wavelength,
Explanation:
Given that,
Mass of the particle,
Acceleration of the particle,
Time, t = 5 s
It starts from rest, u = 0
The De Broglie wavelength is given by :
v = a × t
Hence, this is the required solution.
Answer:
E = 0 r <R₁
Explanation:
If we use Gauss's law
Ф = ∫ E. dA = / ε₀
in this case the charge is distributed throughout the spherical shell and as we are asked for the field for a radius smaller than the radius of the spherical shell, therefore, THERE ARE NO CHARGES INSIDE this surface.
Consequently by Gauss's law the electric field is ZERO
E = 0 r <R₁
Answer:
a)
b)
c)
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height
To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height
So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point
Solving the quadratic equation
So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:
Since the projectile is going down the velocity at the instant it reaches the ground is: