At position of maximum height we know that the vertical component of its velocity will become zero
so the object will have only horizontal component of velocity
so at that instant the motion of object is along x direction
while if we check the acceleration of object then it is due to gravity
so the acceleration of object is vertically downwards
so it is along y axis
so here these two physical quantities are perpendicular to each other
so correct answer would be
<em>C)At the maximum height, the velocity and acceleration vectors are perpendicular to each other. </em>
Thiết bị không phải nguồn điện:
Đáp án D
Answer:
The first frequency of audible sound in the speed sound is
f = 662 Hz
Explanation:
vs = 344 m/s
x = 52 cm * 1 / 100m = 0.52m
The wave length is the distance between the peak and peak so
d = 2x
d = 2*0.52 m
d = 1.04 m
So the frequency in the speed velocity is
f = 1 / T
f = vs / x = 344 m/s / 0.52m
f ≅ 662 Hz
A because the girl in that instant is not moving up or down so
( up forces)=(down forces )
The up forces is the tension of the rope and down forces us mg -the gravitational force on the girl by the earth
The answer is D. I hope this helps
