Answer:
F = 1300 N
Explanation:
F = mv²/R = 0.4(100²)/3 = 1333.3333...
Assuming it is on a horizontal surface:
friction = μR
R = 20g (g is gravity 9.81)
so Friction = 0.085 x 20g
Work done is force x distance
so Work done = 0.085 x 20g x 28
= 466.956 J
Answer: C. Steel
Explanation: When a sound wave travels through a solid body consisting
of an elastic material, the velocity of the wave is relatively
high. For instance, the velocity of a sound wave traveling
through steel (which is almost perfectly elastic) is about
5,060 meters per second. On the other hand, the velocity
of a sound wave traveling through an inelastic solid is
relatively low. So, for example, the velocity of a sound wave
traveling through lead (which is inelastic) is approximately
1,402 meters per second.
Answer:
5.71428571422 m/s
Explanation:
u = Initial velocity = 20 m/s
v = Final velocity
s = Displacement
a = Acceleration
Time taken = 15-1 = 14 s
Distance traveled in 1 second = 


The speed as she reaches the light at the instant it turns green is 5.71428571422 m/s
Answer:
No, The Moon, on the other hand, rotates once around its every 28 days, and once around the Earth in that same 28 days. The result of this combination is that the same side of the Moon is always facing the Earth.