When a light wave encounters an object, they are either transmitted,reflected,absorbed,refracted,diffracted, or scattered depending on the wave
Answer:
a. 150 N
Explanation:
Gravitational Force: This is the force that act on a body under gravity.
The gravitational force always attract every object on or near the earth's surface. The earth therefore, exerts an attractive force on every object on or near it.
The S.I unit of gravitational force is Newton(N).
Mathematically, gravitational force of attraction is expressed as
(i) F = GmM/r² ........................ Equation 1 ( when it involves two object of different masses on the earth)
(ii) F = mg ............................... Equation 2 ( when it involves one mass and the gravitational field).
Given: m = 17 kg, g = 8.8 m/s²
Substituting into equation 2,
F = 17(8.8)
F = 149.6 N
F ≈ 150 N.
Thus the gravitational force = 150 N
The correct option is a. 150 N
Answer:
138.18 minutes
Explanation:
= Latent heat of water at 0°C = 80 cal/g
m = Mass of water = 570 g
Heat removed for freezing
Let N be the number of cycles and each cycle removes 56 cal from the freezer.
So,
Each cycle takes 10 seconds so the total time would be
The total time taken to freeze 138.18 minutes
The figure mentioned on the question is in the attachment.
Answer: a) 
= - 38.35N
b) 
= 30.5 N
c) 
= 27.45 N
d) a = - 13.16 m/s²
Explanation: A block on an inclined plane has 3 forces acting on it:
- Force due to gravity
= m.g; - Normal Force due to the plane;
- Force of Friction = µ.N;
Since the plane is inclined, Normal Force is equal the y-component of the force due to gravity and Force of friction and the x-component of the force due to gravity are opposite forces.
The second attachment ilustrate the forces acting on the block.
Calculating:
A) The magnitude of the x-component of Force due to gravity:
According to the second image:
= P.sinθ
= 5.9.8.sin(36.8)
= - 38.35 N
B) = 
= m.g.cosθ
= 5.9.8.cos(36.8)
= 30.5 N
C) = 0.9.30.5
= 27.45 N
D) For the acceleration, use Newton's Law: 
= m . a
If there is movement, it is only on x-axis, so the net force is:
- = m.a
- 38.35 - 27.45 = 5a
a = - 13.16 m/s²
The value of acceleration shows there is <u>no</u> <u>movement</u> on the x-axis due to the friction.
Answer:
Explanation:
Let the tension in the cord be T₁ and T₂ .
for motion of block placed on horizontal table
T₁ = m a , a is acceleration of the whole system .
for motion of hanging bucket of mass m
mg - T₂ = ma
adding the two equation
mg + T₁- T₂ = 2ma
for rotational motion of the pulley
torque = moment of inertia x angular acceleration
(T₂ - T₁) R = I x α , I is moment of inertia of pulley , α is angular acceleration .
(mg - 2ma ) R = I x α
(mg - 2ma ) R = I x a / R
(mg - 2ma ) R² = I x a
mgR² = 2ma R² + I x a
a = mgR² / (2m R² + I )
Since body moves by distance d in time T
d = 1/2 a T²
a = 2d / T²
mgR² / (2m R² + I ) = 2d / T²
mgR²T² = 2d x (2m R² + I )
mgR²T² - 4dm R² = 2dI
m R² ( gT² - 4d ) = 2dI
I = m R² ( gT² - 4d ) ] / 2d .
