Answer: D
Rs = 10.0 m/s
The speed of the boat relative to an observer standing on the shore as it crosses the river is 10.0m/s
Explanation:
Since the boat is moving perpendicular to the current of the river, the speed of the boat has two components.
i. 8.0m/s in the direction perpendicular to the current
ii. 6.0m/s in the direction of the current.
So, the resultant speed can be derived by using the equation;
Rs = √(Rx^2 + Ry^2)
Taking
Ry = 8.0m/s
Rx = 6.0m/s
Substituting into the equation, we have;
Rs = √(6.0^2 + 8.0^2)
Rs = √(36+64) = √100
Rs = 10.0 m/s
The speed of the boat relative to an observer standing on the shore as it crosses the river is 10.0m/s
potential energy = mass × gravity × height
so, change in potential energy = mass × gravity × change in height
2 = 50 × 10 × Δh
2 ÷ 500 = Δh
Δh = 0.004 m
This distance does depend on the initial velocity of the ball.
screwdriver :)
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Answer:
option D is correct
Explanation:
It is important to note that equipotential lines are always perpendicular to electric field lines. No work is required to move a charge along an equipotential, since ΔV = 0. Thus the work is :
W = −ΔPE = −qΔV = 0.
Work is zero if force is perpendicular to motion. Force is in the same direction as E, so that motion along an equipotential must be perpendicular to E. More precisely, work is related to the electric field by:
W = Fd cos θ = qEd cos θ = 0.
- The change in kinetic energy Δ K.E by conservation should be:
Δ K.E = W
Since, W = 0:
Δ K.E = 0
- If change in kinetic energy is zero it means that charge moves at a constant speed. Hence, option D is correct.
