True. Their immune system weakens and they stay sick until they die.
-- <em>Mechanical waves DO</em> require a medium in order to travel from place to place. (Sound can't travel without some material to travel through on the way.)
-- <em>Electromagnetic waves do NOT</em> need a medium in order to travel from place to place. (Sunlight reaches us from the Sun without anything to travel through on the way.)
Answer:
-540 kJ
Explanation:
P = Pressure which is applied to the piston = 180 kPa
= Final volume = 2 m³
= Initial volume = 5 m³
Work done is given by
The work required to compress helium is -540 kJ
Answer:
Explanation:
One of the easiest ways to work with vectors is to use their components
a) To find the magnitude let's use the Pythagorean theorem
A² = Ax² + Ay² + Az²
A = √ 3² + 4² + (-5)² = √ 50
A = 7.07
B = √ Bx² + By² + Bz²
B = √ (-2)² + 0 + 6² = √ 40
B = 6.32
b) to find these angles the most practical use the concept of cosine directors with the formulas
Vector A
cos α = X / A
cos β = y / A
cos γ = z / A
cos α = 3 / 7.07
α = cos⁻¹ 0.424
α = 64.9º
cos β = 4 / 7.07
β = cos⁻¹ 0.5658
β = 55.5º
Cos γ = -5 / 7.07
γ=Cos⁻¹ (-0.7079)
γ= 135º
Vector B
cos α = X / B
cos β = y / B
cos γ = z / B
cos α = 0
α = 90º
cos β = -2 / 6.32
β = 108.4º
cos γ = 6 / 6.32
γ = 18.3º
c) find A + B
R = A + B = (3 + 0) i ^ + (4-2) j ^ + (-5 +6) k ^
R = 3 i ^ + 2j ^ + 1 k ^
d) to find the angles we use the scalar product
cos θ = A.B / | A | | B |
A.B = 0 i ^ -8 j ^ -30 k ^
Cos θ = [R (8 2 + 30 2)] / 7.07 6.32
Cos θ = 31.05 / 44.68
θ = 46º
e) find A-B
R = A-B = (3-0) i ^ + (4- (2)) j ^ + (-5 - 6) k ^
R = 3 i ^ + 6j ^ -11 k ^
Answer:
Tangential velocity = 10.9 m/S
Explanation:
As per the data given in the question,
Force = 20 N
Time = 1.2 S
Length = 16.5 cm
Radius = 33.0 cm
Moment of inertia = 1200 kg.cm^2 = 1200 × 10^(-4) kg.m^2
= 1200 × 10^(-2) m^2
Revolution of the pedal ÷ revolution of wheel = 1
Torque on the pedal = Force × Length
= 20 × 16.5 10^(-2)
= 3.30 N m
So, Angular acceleration = Torque ÷ Moment of inertia
= 3.30 ÷ 12 × 10^(-2)
= 27.50 rad ÷ S^2
Since wheel started rotating from rest, so initial angular velocity = 0 rad/S
Now, Angular velocity = Initial angular velocity + Angular Acceleration × Time
= 0 + 27.50 × 1.2
= 33 rad/S
Hence, Tangential velocity = Angular velocity × Radius
= 33 × 33 × 10^(-2)
= 10.9 m/S
