Answer:
a) 0.036 J b) 0.036J c) 0.036 d) 1.9m/s e) 0.18 m
Explanation:
Mass of the dart = 0.02kg, the spring was compressed to 6cm
Work needed to compress the spring = 1/2*k*x ^2 where k is the force constant of the spring in N/m, x is the distance it was compressed in m
Work needed to compress the spring = 0.5 * 20* 0.06^2 since 6cm = 6 / 100 = 0.06 m
Work needed to compress the spring = 0.036J
b) the total energy stored in the spring = the work done to compress the spring = 0.036J
c) kinetic energy of the dart as it leaves the the spring = elastic potential energy stored in the spring = the work done in compressing the = 0.036J using the law of conservation of energy; energy is neither created nor destroyed but transformed from one form to another.
d) 1/2mv^2 = 0.036
mv^2 = 0.036*2
v^2 = 0.036*2 / 0.02 = 3.6
v = √3.6 = 1.897 approx 1.9m/s
e) kinetic energy of the dart = work done against gravity to get the body to height h
Work done against gravity = potential energy conserved at height = -mgh g is negative because the motion is upward while gravity acts downward
0.036 = 0.02 * 9.81 * h
0.036 / ( 0.02*9.81) = h
h = 0.18 m
The answer is C. Elements
Elements cannot be broken down int simpler substances even by chemical means
Answer:
16
Explanation:
6+10=16
the box will go forward but it will be a little harder.
The answer would possibly be H in my mind
2.3 seconds
Ignoring air resistance, the flight time is merely a function of gravity and vertical velocity. The vertical velocity will be the initial velocity multiplied by the sine of the angle above the horizon. So:
V = sin(72)*12 m/s
V = 0.951056516 * 12 m/s
V = 11.4126782 m/s
Gravitational acceleration is 9.8 m/s, so divide the vertical velocity by gravitational acceleration to get how long it takes for the ball to reach its apex.
11.4126782 m/s / 9.8 m/s^2 = 1.164559 s
And the old saying "What goes up, must come down" really applies here. And conveniently, it's also symmetric, in that the time it takes to fall will match the time it takes to reach its apex. So multiply the time by 2.
1.164559 s * 2 = 2.329117999 s
Rounding the result to 2 significant figures gives 2.3 seconds.
