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Explanation:
A wall that is acted upon by a force of 20N does not move suggests that no work has been done on the wall.
Work done is the force applied to move in the direction of the applied force.
Work done = force x distance.
Since the distance is 0, the work done on the body too is zero.
Work is only done when forces moves a body through a given distance.
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Answer:
Explanation:
velocity of first projectile after 3 s
v = u - gt
v = 49.4 - 9.8 x 3
= 20 m /s
Velocity of second projectile after 3 s after being dropped from rest
v = u + gt
= 0 + 9.8 x 3
= 29.4 m /s
They will be moving in opposite direction at the time of meeting , so their relative velocity
= 20 + 29.4 = 49.4 m /s
From the frame of reference of the first projectile, the velocity of the second projectile will be 49.4 m /s .
Answer:
The Force between the two charges is an attractive force of 16,000N
Explanation:
Expression for the electric force between the two charges is given by
F = (k*q1*q2) / r^2
Here, k = constant = 9 x 10^9 N*m^2 / C^2
q1 = - 2.0x10^-4C
q2 = + 8.0x10^-4C
r = 0.30 m
Substitute the given values in the above expression -
One charge is + and the other is a -, therefore the net force is an attractive force (opposites atract)
The attraction force is:
F= 9.0x10^9 * 2.0x10^-4 *8.0x10^-4 N/ 0.30^2
F= 16,000N
