Answer:
a = 0.7267
, acceleration is positive therefore the speed is increasing
Explanation:
The definition of acceleration is
a = dv / dt
they give us the function of speed
v = - (t-1) sin (t² / 2)
a = - sin (t²/2) - (t-1) cos (t²/2) 2t / 2
a = - sin (t²/2) - t (t-1) cos (t²/2)
the acceleration for t = 4 s
a = - sin (4²/2) - 4 (4-1) cos (4²/2)
a = -sin 8 - 12 cos 8
remember that the angles are in radians
a = 0.7267
the problem does not indicate the units, but to be correct they must be m/s²
We see that the acceleration is positive therefore the speed is increasing
A water wave is an example of a mechanical wave. A wave that can travel only through matter is called a mechanical wave.
Answer:
M = ρ V = 9 gm/cm^ 3 * cm^3 = 27 gm
a = (V2 - V1) / t = (6 - 2) m/s / 12 s = 1/3 m/s^2 the acceleration
F = M a = 27 gm * 1/3 m/s^2 = 9 dynes net force applied
Answer:
E) d/sqrt2
Explanation:
The initial electric force between the two charge is given by:

where
k is the Coulomb's constant
q1, q2 are the two charges
d is the separation between the two charges
We can also rewrite it as

So if we want to make the force F twice as strong,
F' = 2F
the new distance between the charges would be

so the correct option is E.
Answer:
A) v_average = - 10 km / h, B) v = 1.6 m / s, v = 17.6 m / s
Explanation:
A) the average speed is the average speed of a body, if we assume that the direction of going up the hill is positive
v₁ = 40 km / h
v₂ = - 60 km / h
the average speed is
v_average =
v_average = ( 40 - 60)/2
v_average = - 10 km / h
B) in this case they indicate the acceleration a = 3.2 m / s² and the velocity vo = 9.6 m / s
i) the speed for 2.5 s above
v = v₀ + a t
as the time is earlier
t = - 2.5 s
we substitute
v = 9.6 - 3.2 2.5
v = 1.6 m / s
ii) the velocity for a subsequent time of 2.5 s
t = 2.5 s
we substitute
v = 9.6 + 3.2 2.5
v = 17.6 m / s