From the equations of linear motion,
v² = u² + 2as where v is the final velocity, u is the initial velocity and a is the gravitational acceleration, and s is the displacement,
Thus, v² = u² -2gs, but v=0
hence, u² = 2gs
= 2×9.81×0.43
= 8.4366
u = √8.4366
=2.905 m/s
Hence the initial velocity is 2.905 m/s
Then using the equation v= u +gt .
Therefore, v = u -gt. (-g because the player is jumping against the gravity)
but, v = 0
Thus, u= gt
Hence, t = u/g
= 2.905/9.81
= 0.296 seconds
Answer:cart B
Explanation:
For cart A speed is constant therefore there is no acceleration because acceleration is rate of change of velocity
thus there is no net force
For cart B there is change in velocity in the left direction , so there is net acceleration towards left
so there is net force in the left direction
For cart C there is decrease in velocity i.e. negative acceleration or deceleration . Therefore there is a net force towards right which opposes the motion
Answer:
E. 3h
Explanation:
We know that
u = 0 m/s.
velocity after t = 1s
v = u+gt = 0+9.81 x 1s= 9.81 m/s
distance covered in 1st sec
= =>> ut+0.5 x g x t²
=>>0 + 0.5x 9.81 x 1 = 4.90m
Let 4.90 be h
distance travelled in 2nd second will now be used
So velocity after t = 1s
=>>1 x t+ 0.5 x g x t²
=>9.81x 1 + 0.5 x 9.81 x 1 = 3 x 4.90
So since h= 4.90
Then the ans is 3x h = 3h
The velocity is 4374.45 m/s.
I got the answer by using v=d/t.
20,000meters / 25min= 4,374.45 m/s.
<span>The correct answer is "velocity, height". Kinetic energy is affected by: mass and velocity, while potential energy by: mass, gravity and height (or "position"). Considering these combinations, only the third choice is the correct one: a) position, gravity describe only potential energy, B) gravity, position describe only potential energy, C) velocity, height describe respectively kinetic and potential energy, D) height, velocity would respectively describe potential energy first and then kinetic energy, it is in the wrong order, thus the correct answer is C.</span>
