a. The ball's horizontal and vertical positions at time are given by
The ball reaches the net when :
At this time, the ball is at an altitude of
which is 1.40 m - 0.900 m = 0.500 m above the net.
b. The change in angle gives the ball the new position functions
The ball reaches the net at time such that
at which point the ball's vertical position would be
so that the ball does not clear the net with 0.343 m - 0.900 m = -0.557 m.
Answer:
(a) 2.03 m/s
(b) 2.15 m/s
Explanation:
(a)
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where
is the common velocity,
and
are velocities of the first railroad car and the second railroad car respectively,
and
are masses of the first railroad car and the second railroad car respectively
Substituting the given figures then
(b)
Momentum, p=mv where m is the mass and v is the velocity
where
and
are initial velocities of the ball moving towards west and the other ball moving in opposite direction respectively,
and
are masses of the first railroad car and the second railroad car respectively
Taking west as positive then the opposite direction will be negative hence
Note that when the 0.455 rebounds, it moves towards East and since we took West as positive that is why we give 15.4 as a negative value.
towards East