Answer:
the friction force in the reverse direction is 200 *0.4=80 N.
the net forward force acting on the box is therefore
Fnet= 100 - 80 N
= 20 N
acceleration = Fnet / mass
=Fnet *g/(weight)
=20 *9.8/200 = 0.98 m/s^2
Explanation:
Answer:
A model rocket is launched with an initial upward velocity of 215 ft/s.
Explanation:
Answer:
70 m.
Explanation:
Given,
Frequency, f = 20 HZ
speed of sound, v = 1400 m/s
wavelength of the waves = ?
we know,
v = f λ



Hence, the wavelength of the wave is equal to 70 m.
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.
Explanation:
The energy of the wave will decrease.
The energy of a wave is given as
E = h f
where E = energy of waver
h = plank's constant
f = frequency of the wave.
From the formula , we see that the energy of the wave is directly proportional to the frequency of the wave. hence as the frequency of the wave decrease, the energy of the wave will decrease.