Answer:
The planets spun in epicycles.
Explanation:
The planets were not simply attached to a mystical sphere (“deferent”) but they were actually attached to a mini-sphere (“epicycle”) which rotated on the larger one.
The answers is 30 miles per hour, the driver is speeding the car up, section-H, 12 minutes, section-D, and 65 miles per hour.
Answer:
5.5 m/ sec
Explanation:
Because the inclined surface is frictionless so we can assume that total change of energy is zero
i-e ΔE = 0
Or we can say that difference between final and initial energy is zero i-e
Ef- Ei =0
Where,
Ef= final energy at the top of the ramp= KEf+PEf
Ei= Initial energy at the bottom of the ramp=KEi+PEi
So we have
(KEf+PEf)-(KEi+PEi)=0
==>KEf-KEi+PEf-PEi=0 -------------(1)
KEf = mgh = 200×9.8×h
Where h= Sin 22 = h/d= h/4.1
or
0.375×4.1=h
or h= 1.54 m
So, PEf= 200×9.8×1.54=3018.4 j
and KEf= 1/2 m
= 0.5×200×0=0 j
PEi= mgh = 200×9.8×0=0 j
KEi= 1/2 m
=0.5×200×
=100
j
Put these values in eq 1, we get;
0-100
+3018.4-0=0
-100
=-3018.4
==>
= 30.184
==> Vi = 
Answer:
F = 1500 [N]
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of all forces must be equal to the product of mass by acceleration.
ΣF = m*a
F = 1000*1.5
F = 1500 [N]
Answer:
30N in the direction the 45N acts.
Explanation:
Fnet = F1 + F2 (the vector sum of the forces)
Assigning a positive direction to the 45N force and a negative direction to the 15N force gives:
Fnet = 45 - 15
Fnet = 30N
Since the answer is positive, it is in the direction the 45N force acts.