A boy swings a ball on a string at constant speed in a circle that has a circumference equal to 6 m. What is the work done on th
e ball by the 10 N tension force in the string during one revolution of the ball
1 answer:
Answer:
0 J
Explanation:
From the diagram below; we would notice that the Force (F) = Tension (T)
Also the angle θ adjacent to the perpendicular line = 90 °
The Workdone W = F. d
W = Fd cos θ
W = Fd cos 90°
W = Fd (0)
W = 0 J
Hence the force is perpendicular to the direction of displacement and the net work done in a circular motion in one complete revolution is = 0
You might be interested in
Answer:
3.0 seconds
Explanation:
The time of flight of a projectile (the time it takes to reach the ground) does not depend on the horizontal motion, but only on its vertical motion.
In fact, the time of flight is determined by the suvat equation:
where
s is the vertical displacement
u is the initial vertical velocity (0, in case of these two projectiles)
g = 9.8 m/s^2 is the acceleration of gravity (assuming downward as positive direction)
t is the time of flight
Re-arranging the equation, we get
We see that this time depends only on s (the heigth of the cliff) and g: therefore, since the two projectiles are launched from the same height, they take the same time to reach the ground, 3.0 seconds.