Answer:
120 m/s²
Explanation:
25 – 0 / 2.1 = 119.0476 = 120 m/s² to two significant figures
The object's kinetic energy changes according to
d<em>K</em>/d<em>t</em> = 15 J/s
If <em>v</em> is the object's initial speed, then its initial kinetic energy is
<em>K</em> (0) = 1/2 (5 kg) <em>v</em> ²
Use the fundamental theorem of calculus to solve for <em>K</em> as a function of time <em>t</em> :
After <em>t</em> = 13 s, the object's kinetic energy is
<em>K</em> (13 s) = 1/2 (5 kg) (13 m/s)² = 422.5 J
Put this as the left side in the equation above for <em>K(t)</em> and solve for <em>v</em> :
==> <em>v</em> ≈ 9.5 m/s
Frequency is no. of times this wave vibrates or complete its one cycle per unit time. As it vibrates 30000 times per second its frequency is 30000 per second or 30000 Hz [1 Hz = once per second].
Answer:
The acceleration of the box is 3 m/s²
Explanation:
Given;
mass of the box, m = 12 kg
horizontal force pulling the box forward, Fx = 48 N
frictional force acting against the box in opposite direction, Fk = 12 N
The net horizontal force on the box, F = 48 N - 12 N
The net horizontal force on the box, F = 36 N
Apply Newton's second law of motion to determine the acceleration of the box;
F = ma
where;
F is the net horizontal force on the box
a is the acceleration of the box
a = F / m
a = 36 / 12
a = 3 m/s²
Therefore, the acceleration of the box is 3 m/s²
