Answer:
The elevator must be <u>accelerating upward</u> as the net force acting is upward.
Explanation:
Given:
Original weight of the student, 
Reading on the spring scale is the normal reaction by the scale on the student and is given as, 
The normal reaction acts in the upward direction while the weight of the student acts vertically downward.
Now, the magnitude of the normal reaction is greater than the magnitude of the weight. Therefore, the net force acting on the student is given as:
Therefore, the net force is acting vertically upward.
Now, as per Newton's second law, the direction of the net acceleration acting on a body is the same as the direction of the net force acting on it.
Thus, the elevator must be accelerating upward as the net force acting is upward.
Answer:
θ₁ = 3.35 10⁻⁴ rad
, θ₂ = 8.39 10⁻⁵ rad
Explanation:
This is a diffraction problem for a slit that is described by the expression
sin θ = m λ
the resolution is obtained from the angle between the central maximum and the first minimum corresponding to m = 1
sin θ = λ / a
as in these experiments the angle is very small we can approximate the sine to its angle
θ = λ / a
In this case, the circular openings are explicit, so the system must be solved in polar coordinates, which introduces a numerical constant.
θ = 1.22 λ / D
where D is the diameter of the opening
let's apply this expression to our case
indicates that the wavelength is λ = 550 nm = 550 10⁻⁹ m
the case of a lot of light D = 2 mm = 2 10⁻³ m
θ₁ = 1.22 550 10-9 / 2 10⁻³
θ₁ = 3.35 10⁻⁴ rad
For the low light case D = 8 mm = 8 10⁻³
θ₂ = 1.22 550 10-9 / 8 10⁻³
θ₂ = 8.39 10⁻⁵ rad
Answer:
As the skydiver falls to the Earth, she experiences positive acceleration only due to gravity.
Explanation:
As the skydiver falls to the Earth, she experiences friction in the form of air resistance which tries to slow her down and is proportional to the her velocity. So it cannot have a positive acceleration as it acts in opposite direction to slow her down.
Inertia during skydiving is experienced when we open an parachute, the parachute slows down the speed of are descent hence changing our inertia of motion with a velocity.
Only the Earth's, gravitational field has an positive acceleration as it pulls us towards the Earth, hence increasing our velocity.
Answer:
i. F = 1.3 x 
N
ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself (i.e a pull).
Explanation:
Since the given charges are opposite, then the force of attraction is experienced. The force of attraction between the two charges can be determined by:
F = 
where F is the force, k is the constant, 
is the charge of the electron, 
is the charge on the proton, and d is the distance between them.
So that; k = 9.0 x 
N
, = 1.6 x 
C, = 1.6 x
Thus,
F = 
= 
= 1.3061 x
F = 1.3 x N
The force between the charges is 1.3 x N.
ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself.
Refer to the diagram shown below.
The weight of the block is
W = (2.41 kg)*(9.8 m/s²) = 23.618 N
The kinetic coefficient of friction is
μ = 0.521
The normal reaction is
N = f cos(59.9°) = 0.5015f N
The frictional resistive force is
R = μN = 0.521*(0.5015f N) = 0.2613f N
For dynamic force balance,
f sin(59.9°) = W + R
0.8652f = 23.618 + 0.2613f
0.6039f = 23.618
f = 39.109 N
The block moves by 1.42 m.
The work done is
W = (f sin(59.9° N)*(1.42 m)
= 39.109*sin(59.9°)*1.42
= 48.05 J
Answer: 48.0 J (nearest tenth
