At the ground the ball will always have velocity along the direction of gravity. If upward motion is taken positive it will always have negative velocity at the ground because, if the ball was given an initial upward velocity then gravity will decelerate it and bring it down with a negative final velocity. If the ball is given an initial downward velocity then the ball will be further accelerated by gravity in the downward direction only, again maintaining negative direction. The magnitude however in both cases will be different. the final velocity at the ground will have higher magnitude in case of elevator moving downwards.
Answer:
Explanation:
331 m/s / 2.5e4 cyc/s = 0.01324 m ≈ 1.3 cm
Answer: height = 3.98m
Explanation: by placing the watermelon at a height above the ground, it has a potential energy of the formulae
p = mgh
p = potential energy = 4.61kJ = 4610J
m = mass of watermelon = 118 kg
g = acceleration due gravity = 9.8 m/s²
4610 = 118 * 9.8 * h
h = 4610/ 118 * 9.8
h = 4610/ 1156.4
h = 3.98m
Explanation:
Terminal velocity is given by:

Here, m is the mass of the falling object, g is the gravitational acceleration,
is the drag coefficient,
is the fluid density through which the object is falling, and A is the projected area of the object. in this case the projected area is given by:

Recall that drag coefficient for a horizontal skydiver is equal to 1 and air density is
.

Without drag contribution the motion of the person is an uniformly accelerated motion, thus:

Explanation:
A compass needle acts as a Magnet