Answer:
Explanation:
From the given information:
The initial PE 
= m×g×h
= 5 kg × 9.81 m/s² × 10 m
= 490.5 J
The change in Potential energy P.E of the box is:
ΔP.E = 
ΔP.E = 0 -
ΔP.E = 
If we take a look at conservation of total energy for determining the change in the internal energy of the box;
this can be re-written as:
Here, K.E = 0
Also, 70% goes into raising the internal energy for the box;
Thus,
ΔU = 343.35 J
Thus, the magnitude of the increase is = 343.35 J
Answer:
Option d is correct.
Explanation:
We know , resistance of a body is directly proportional to its length and inversely proportional to its area.
( Here, 
is constant dependent on object material )
Writing 
also :
( since they are of same material therefore, is same.)
Now , if 
.
Then 
Therefore, option d. is correct.
Hence, this is the required solution.
to calcukate average speed it's unimportant what happened on the way, but we need onky to know total distance d total time. so average speed was : 240 km / 4 hours = 60 km/h
U = 0, initial upward speed
a = 29.4 m/s², acceleration up to 3.98 s
a = -9.8 m/s², acceleration after 3.98s
Let h₁ = the height at time t, for t ≤ 3.98 s
Let h₂ = the height at time t > 3.98 s
Motion for t ≤ 3.98 s:
h₁ = (1/2)*(29.4 m/s²)*(3.98 s)² = 232.854 m
Calculate the upward velocity at t = 3.98 s
v₁ = (29.4 m/s²)*(3.98 s) = 117.012 m/s
Motion for t > 3.98 s
At maximum height, the upward velocity is zero.
Calculate the extra distance traveled before the velocity is zero.
(117.012 m/s)² + 2*(-9.8 m/s²)*(h₂ m) = 0
h₂ = 698.562 m
The total height is
h₁ + h₂ = 232.854 + 698.562 = 931.416 m
Answer: 931.4 m (nearest tenth)
Answer:
Gravity
Explanation:
The source of the centripetal force that keeps the mass in a stable circle is gravity.
