Answer:
Explanation:
We shall apply conservation of mechanical energy .
initial kinetic energy = 1/2 m v²
= .5 x m x 12 x 12
= 72 m
This energy will be spent to store potential energy . if h be the height attained
potential energy = mgh , h is vertical height attined by block
= mg l sin20 where l is length up the inclined plane
for conservation of mechanical energy
initial kinetic energy = potential energy
72 m = mg l sin20
l = 72 / g sin20
= 21.5 m
deceleration on inclined plane = g sin20
= 3.35 m /s²
v = u - at
t = v - u / a
= (12 - 0) / 3.35
= 3.58 s
it will take the same time to come back . total time taken to reach original point = 2 x 3.58
= 7.16 s
If an object is in motion it will stay in motion
Keplers laws states that planets sweep areas in equal times is second
Given:
The initial velocity of the object, v=30 m/s
a_t=0
a_c≠0
The time period is Δt.
To find:
The right conclusion among the given choices.
Explanation:
a_t represents the tangential accleration on the object and a_c represents the centripetal acceleration on the object.
The centripetal acceleration is the acceleration that keeps the object in its circular path. The centripetal force only changes the direction of the velocity and not the magnitude.
Thus the magnitude of the velocity of the object remains the same after a time interval of Δt. But the direction of the velocity of the object will be changed and will be unknown after Δt seconds.
Final answer:
Thus the object will be traveling at 30 m/s in some unknown direction.
Therefore, the correct answer is option a.
