Answer:
Reaches max height at t = 2.42s.
Explanation:
I've assumed we are neglecting air resistance. If not let me know and I'll update.
We want to examine the behaviour of the ball in the y-direction. In the absence of air resistance the only force acting on the ball is gravity, which produces an acceleration in the negative y direction.
Answer:
Zero, the support force and gravitational force together equal a zero net force
Explanation:
Answer:
40J
Explanation:
Kinetic energy = 1/2 mv^2
Where m = mass and
v = velocity
Given mass = 20kg
v = 2m/s
K.E = 1/2 x 20 x2^2
= 1/2 x 20 x 2 x 2
= 80/2
= 40J
Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
Convection is the movement<span> of groups of molecules within </span>fluids<span> such as gases and liquids, including molten rock (rheid).</span>
