Average speed is defined as the ratio of total distance covered in total given time

here we know that total distance that man moved is


so total distance is



now here total time of the motion is


total time will be given as


now by above formula


so his average speed is 30 km/h
Answer:
For number 2, it will be 8.
Answer:
1.87 A
Explanation:
τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s
d = diameter of copper wire = 2 mm = 2 x 10⁻³ m
Area of cross-section of copper wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
E = magnitude of electric field = 0.01 V/m
e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C
m = mass of electron = 9.1 x 10⁻³¹ kg
n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³
= magnitude of current
magnitude of current is given as


= 1.87 A
Answer:
1.327363 m/s
0.00090243 m
Explanation:
u = Initial velocity
v = Final velocity
m = Mass of flea
Energy

The velocity of the flea when leaving the ground is 1.327363 m/s

The flea will travel 0.00090243 m upward
Force required is 100 N
<u>Given that;</u>
Rate of acceleration = 5 m/s²
Mass of object = 20kg
<u>Find:</u>
Force required
<u>Computation:</u>
Force = Mass × Acceleration
Force required = Rate of acceleration × Mass of object
Force required = 20 × 5
Force required = 100 N
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