3. A simple way to state Newton’s first law is:
1 answer:
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Answer:
New force,
Explanation:
The electrostatic force between two spheres is given by :
According to given condition, each of the spheres has lost half its initial charge, new force is given by :
So, the new force becomes (1/4)th of the initial force. Hence, the correct option is (d).
Answer:
2.551 m/s
Explanation:
Given:
Boulder is dropped from the cliff
thus,
Initial speed of the boulder, u = 0 m/s
Final speed to be obtained, v = 90 km/h =
=25 m/s
also, in the case of free fall the acceleration of the boulder will be equal to the acceleration due to the gravity i.e g = 9.8 m/s²
Now, from the Newton's equation of motion
v = u + at
where, a is the acceleration = g = 9.8 m/s²
t is the time
on substituting the respective values, we get
25 = 0 + 9.8 × t
or
t =
or
t = 2.551 m/s