Answer: The second force applied to the doorknob
Explanation:
The formulae for torque is simple the product of the applied force and the perpendicular distance.
The greater the perpendicular force, the greater the torque assuming a constant value of force.
Applying the force at the doorknob gives for a greater distance between the force and the turning point compared to applying the force at the midpoint of the door ( which is at a shorter distance)
Mass have no effect for the projectile motion and u want to know the height "h"
first,
find the vertical and horizontal components of velocity
vertical component of velocity = 12 sin 61
horizontal component of velocity = 12 cos 61
now for the vertical motion ;
S = ut + (1/2) at^2
where
s = h
u = initial vertical component of velocity
t = 0.473 s
a = gravitational deceleration (-g) = -9.8 m/s^2
h=[12×sin 610×0.473]+[−9.8×(0.473)2]
u can simplify this and u will get the answer
h=.5Gt2
H=1.09m
If both waves have the same wavelength, then the amplitude of
their sum could be anything between 1 cm and 9 cm, depending
on the phase angle between them.
If the waves have different wavelengths, then the resultant is a beat
with an amplitude of 9 cm.