By
vector addition.
In fact, velocity is a vector, with a magnitude intensity, a direction and a verse, so we can't simply do an algebraic sum of the two (or more velocities).
First we need to decompose each velocity on both x- and y-axis (if we are on a 2D-plane), then we should do the algebraic sum of all the components on the x- axis and of all the components on the y-axis, to find the resultants on x- and y-axis. And finally, the magnitude of the resultant will be given by

where Rx and Rx are the resultants on x- and y-axis. The direction of the resultant will be given by

where

is its direction with respect to the x-axis.
By adding a vibration at the natural frequency of the medium-A
Answer:
1.65
Explanation:
The equation of the forces along the horizontal direction is:
(1)
where
F = 65 N is the force applied with the push
is the frictional force
m = 4 kg is the mass
is the acceleration
The force of friction can be written as
(2), where
is the coefficient of kinetic friction
R is the normal force exerted by the floor
The equation of forces along the vertical direction is
(3)
since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find

And solving for
,

I think it is either A or B. I’m mostly leaning towards B.
Answer:
new temperature of the tire will be 278.76 K
Explanation:
when the temperature increases, the particles will have greater kinetic energy and also the pressure will be increase for the gas particles.
so when the temperature increases, pressure will also increase and vice versa
T is directly proportional to P
T1 = initial temperature= 303 k
P1= Initial pressure = 325000 pa
T2= Final temperature= ?
P2= Final pressure = 299000 pa
mathematically
P1/T1= P2/T2
T2= P2 x T1/P1
T2 = 299000 x 303/ 325000= 278.76 k