Answer:
The effective spring constant of the firing mechanism is 1808N/m.
Explanation:
First, we can use kinematics to obtain the initial velocity of the performer. Since we know the angle at which he was launched, the horizontal distance and the time in which it's traveled, we can calculate the speed by:

(This is correct because the horizontal motion has acceleration zero). Then:

Now, we can use energy to obtain the spring constant of the firing mechanism. By the conservation of mechanical energy, considering the instant in which the elastic band is at its maximum stretch as t=0, and the instant in which the performer flies free of the bands as final time, we have:

Then, plugging in the given values, we obtain:

Finally, the effective spring constant of the firing mechanism is 1808N/m.
Answer:
215955.06 m/s^2
Explanation:
length of barrel, s = 0.89 m
initial velocity of the bullet, u = 0 m/s
Final velocity of the bullet, v = 620 m/s
Let a be the acceleration of the bullet in the barrel
Use third equation of motion, we get


a = 215955.06 m/s^2
Thus, the acceleration of the bullet inside the barrel is 215955.06 m/s^2.
Answer:
cold water strengthens the magnetic attractive force.
Explanation:
The molecules within the magnet will move slower because they have less kinetic energy,so there is less vibration within the magnets molecules.
Answer:
Angle of reflection of light is 34 degree
Explanation:
As per law of reflection of light we know that
angle of incidence of light = angle of reflection of light
So here we know that
angle of incidence on the surface of oil is given as

so we know that

so here we can say that reflection angle of light will be same as angle of incidence
