Answer:
300 cos 30 = 40 a + 40 * .2 * 10
Total force = mass * acceleration + frictional force
260 = 40 a + 80
a = 180 / 40 = 4.5 m/s^2
Check:
15 a + 15 * 10 * .2 = T acceleration of 15 kg block (assuming a = 4.5)
T = 15 (4.5) + 30 = 97.5 force required to accelerate 15 kg block
260 - 97.5 = 162.5 net force on 25 kg block
162.5 = 4.5 (25) + 25 * 10 * .2
162.5 = 112.5 + 50 = 162.5
4.5 m/s^2 checks out as correct
Answer:9.8 m/s²
Explanation:
It was going at 9.8m/s² as this is the acceleration of an object due to gravity
when an object falls it accelerates at a consant and uniform speed which is 9.8m/s²
X
Hot air rises = it's less dense than cold air = falls
Answer:
increase
Explanation:
According to Einstein's photoelectric equation; the energy of a photon striking a metal surface is related to the kinetic energy of the ejected photoelectron by the formula;
KE= hf - hfo
Where h is the planks constant, f and fo refer to the frequency of incident photon and the threshold frequency respectively.
Hence, we can clearly see from the foregoing that the kinetic energy of the ejected photoelectron is proportional to the frequency of the incident photon.
Hence, if the frequency of the incident photon is increased, the kinetic energy of the ejected photoelectron increases also.
<h2>The option ( c ) is correct</h2>
Explanation:
When we apply the force on any body , the inertia comes into play . It is the tenancy of the the body to oppose the force which tends to change its state .
In first case the train tries to change its state from rest to motion . Thus the inertia of rest opposes this tendency.
In the second case , the train tries to come from motion to the state of rest . Thus again , inertia opposes it .
Therefore inertia is the factor which creates difficulty in both case . Hence option ( c ) is correct
