Answer:
voltage ÷ resistance; therefore
20 ÷ 4 = 5 amps
Answer:
1.25 kgm²/sec
Explanation:
Disk inertia, Jd =
Jd = 1/2 * 3.7 * 0.40² = 0.2960 kgm²
Disk angular speed =
ωd = 0.1047 * 30 = 3.1416 rad/sec
Hollow cylinder inertia =
Jc = 3.7 * 0.40² = 0.592 kgm²
Initial Kinetic Energy of the disk
Ekd = 1/2 * Jd * ωd²
Ekd = 0.148 * 9.87
Ekd = 1.4607 joule
Ekd = (Jc + 1/2*Jd) * ω²
Final angular speed =
ω² = Ekd/(Jc+1/2*Jd)
ω² = 1.4607/(0.592+0.148)
ω² = 1.4607/0.74
ω² = 1.974
ω = √1.974
ω = 1.405 rad/sec
Final angular momentum =
L = (Jd+Jc) * ω
L = 0.888 * 1.405
L = 1.25 kgm²/sec
Answer:
57 N
Explanation:
Draw a free body diagram. There are three forces:
Weight force mg pulling down.
Normal force N pushing up.
Friction force F pushing horizontally.
Sum of the forces in the y direction:
∑F = ma
N − mg = 0
N = mg
Friction force is the product of normal force and coefficient of friction:
F = Nμ
F = mgμ
F = (65 kg) (9.8 m/s²) (0.09)
F = 57.3 N
Rounded, the friction force is 57 N.
<span>it changes the direction of the input force only
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