Answer:
option A
Explanation:
given,
drive 4 km at 30 km/h and
another 4 km at 50 km/h
average speed for the whole 8 Km trip = ?
time for the trip of first 4 km
distance = speed x time


t₁= 0.1333 hr
time from another 4 km trip


t₂ = 0.08 hr
average speed
s = 37.50 Km/hr
Less than 40 Km/h
the correct answer is option A
Answer:
2.88 × 10⁻¹⁸ C
Explanation:
The charge on a proton and electron are the same and it is = 1.6 × 10⁻¹⁹ C
The net charge electric charge of an iron atom = (number of proton × charge on a proton) + ( number of electron × charge on an electron ) = 26 (e) + 8 (-e) = 26 e - 8 e = 18 e = 18 × 1.6 × 10⁻¹⁹ C = 2.88 × 10⁻¹⁸ C
Answer:
<em>264 m</em>
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Explanation:
The complete question is
Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v = 0.75c
using the length contraction relationship,

where 
is the relativistic length
is the actual length = 400 m
v is the velocity of the spaceship
c is the speed of light
since v = 0.75c
v/c = 0.75
substituting, we have
= 400 x 0.66 = <em>264 m</em>
A person's mass would not change before, during, or after a trip to Saturn, unless he gained or lost some weight as a result of unrelated eating habits, because mass doesn't depend on an object's location, gravitational environment, color, cost,
texture, temperature, political affiliation or gender orientation.
Answer:
New angular speed changes from 16 rpm to 19.95 rpm
Explanation:
In the given system the angular momentum of the system is conserved
initial angular momentum of the system

When 28 kg child moves to the center the moment of inertia changes thus we have

Equating initial and final angular momentum we get
