By factorys. Because the smoke that builds up from them
Answer:
the knee extensors must exert 15.87 N
Explanation:
Given the data in the question;
mass m = 4.5 kg
radius of gyration k = 23 cm = 0.23 m
angle ∅ = 30°
∝ = 1 rad/s²
distance of 3 cm from the axis of rotation at the knee r = 3 cm = 0.03 m
using the expression;
ζ = I∝
ζ = mk²∝
we substitute
ζ = 4.5 × (0.23)² × 1
ζ = 0.23805 N-m
so
from; ζ = rFsin∅
F = ζ / rsin∅
we substitute
F = 0.23805 / (0.03 × sin( 30 ° )
F = 0.23805 / (0.03 × 0.5)
F F = 0.23805 / 0.015
F = 15.87 N
Therefore, the knee extensors must exert 15.87 N
The scalar operates only on the magnitude of the vector.
So the length of the vector may change ... becoming longer
or shorter ... but its direction doesn't change.
I., II., and IV. are examples of acceleration. III. isn't.
Answer:
Explanation:
Magnetic field B = 5 x 10⁻³ T
Speed of electron
= ( 5.5 /100) x 3 x 10⁸
= 165 x 10⁵ m /s
Magnetic force on electron
F = Bqv
B is magnetic field , q is charge on electron and v is its velocity
= 5 x 10⁻³ x1.6 x 10⁻¹⁹ x 165 x 10⁵
1320 x 10⁻¹⁷ N
13.2 X 10⁻¹⁵ N
= 13.2 f N
b )
Acceleration = force / mass of electron
= 1320 x 10⁻¹⁷ / 9.1 x 10⁻³¹
= 14.5 x 10¹⁵ m/s²
= 14.5 Pm/s²
c ) The direction of the moving electron will change but its speed will remain constant.
This is so because the magnetic force will be acting perpendicular to the velocity of electron all the time in course of its motion.