Answer:
The time taken by the duck to cross the lake is, t= 4 s
Explanation:
Given data,
The initial speed of the ducks, u = 3 m/s
The final speed of the ducks, v = 7 m/s
The acceleration of the duck, a = 1 m/s²
The formula for the acceleration is,
a = (v - u) / t
∴ t = (v - u) / a
Substituting the given values in the above equation,
t = (7 - 3) / 1
= 4 s
Hence, the time taken by the duck to cross the lake is, t= 4 s
Answer:B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
Explanation:
Answer: Smaller than ; larger than
Explanation:
When the elevator is moving in the upward direction, then the force acting on it is negative in nature because of
N= mg +ma, (g is gravity and a is acceleration)
here ma is negative so the N= mg-ma
Hence, it feels smaller than its original weight.
When the elevator is moving downward , then the force acting will be positive in nature
N= mg+ma,
here ma will be positive so it feels larger the original weight of passenger.
