When an object falls or is dropped from rest it's initial velocity is zero.
Using the equations for a motion in straight line. I can find the time it takes to reach 3.0 m down (half way).
x = vt - 4.9t²
-3 = 0 - 4.9t²
-3/-4.9 = t²
0.6122 = t²
0.7825 sec = t
v = v - gt
v = 0 - 9.8(0.7825)
v = -7.67 m/s
the negative denotes downward direction.
You could also solve the problem using potential and kinetic energy.
Since it starts with maximum PE and gets converted to KE when it hits the ground. mgh = mv²/2
mass cancels, use 3 meters for the halfway distance
-9.8(-3) = v²/2
29.4 * 2 = v²
√(58.8) = 7.67 m/s downwards
Answer:
Explanation:
Using the equation of motion to get the acceleration due to gravoty of the rock on the planet.
S = ut+ 1/2at² where;
S is the distance of the rock above the surface of the planet = 100m
u is the initial velocity = 15m/s
a is the acceleration due to gravity
t is the time taken by the rock to reach the ground = 10s
Since the rock is thrown upward the acceleration due to gravity will be negative i.e a= -g
The equation becomes S = ut- 1/2gt²
Substituting the given value to get the time t
100 = 15(10)- 1/2g(10)²
100 = 150-50g
100-150 = -50g
-50 = -50g
g = -50/-50
g = 1m/s²
<em>Hence the acceleration due to gravity of the rock when it is on Planet XX is 1m/s²</em>
Conservation means to improve something to prevent loss or decay
That's why energy can't be created or destroyed
Answer:
41 turns
Explanation:
= Induced emf = 12.4 mV
= Current changing rate = 0.0275 A/s
L= Inductance
= Average flux = 0.00285 wb
N = Number of turns
Change in flux is given by
Flux through each turn is given by
The number of turns is 41
Answer:
23.5
Explanation:
Dunno how 2 explain but this is correct 4 sureeeeee.