Explanation:
potential energy= mgh
30 × 10 × 30 = 9000J or 9KJ
Answer:
6.16 m/s
0.0105 m
Explanation:
Let the ground 0 for potential reference be at where the spring is compress 0.24 m. The the man would jump from a height h = 2.5 + 0.24 = 2.74 m from it. We can apply the law of energy conservation knowing that as the man jumps, his potential energy converts to kinetic energy, then finally to elastic energy:
where m = 80 kg is the man mass, g = 9.81 m/s2 is the gravitational acceleration, h = 2.74 m is the potential distance he travels, k N/m is the spring constant and x = 0.24 is the distance it compresses
Similarly at the position where it compresses by 0.12 m, it's 0.24 - 0.12 = 0.12 m far from ground 0.
When he steps gently, then his gravity force would equal to his spring force
Answer:
Well the reason that elephants have big ears in the first place is to cool off. They flap their ears and use them as fans.
Answer:
v = - 1,715 m / s
, x = 0.0156 m
Explanation:
This is an oscillatory movement exercise, which is described by the expression
x = A cos (wt + Ф)
we can assume that the block is released from its maximum elongation, so the phase constant (Ф) is zero
As we are told that the stone does not affect the movement of the spring mass system, the amplitude and angular velocity do not change, in the upward movement the stone is attached to the mass, but in the downward movement the mass has an acceleration greater than g leave the stone behind, let's look for time, for this we use the definition of speed and acceleration
v = dx / dt
v = - A w sin wt
a = - Aw² cos wt
a = -g
-g = - Aw² cos wt
wt = cos⁻¹ (g / Aw²)
t = 1 / w cos⁻¹ (g / Aw²)
angular velocity and frequency are related
w = 2π f
w = 2π 4
w = 8π rad / s
remember that the angles are in radians
t = 1 / 8π cos⁻¹ (9.8 / (0.07 64π²))
t = 0.039789 1.3473
t = 0.0536 s
let's find the speed for this time
v = - A w sin wt
v = - 0.07 8π sin (8π 0.0536)
v = - 1,715 m / s
the distance is
x = A cos wt
x = 0.07 cos (8π 0.0536)
x = 0.0156 m
The SI unit of mass is the kilogram, and
the SI unit of force is the Newton.
