Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
The speed 
of the elevator at the beginning of the 8 m descent is nearly 4 m/s. Hence, option A is the correct answer.
We are given that-
the mass of the elevator (m) = 1000 kg ;
the distance the elevator decelerated to be y = 8m ;
the tension is T = 11000 N;
let us determine the acceleration 'a' by using Newton's second law of motion.
∑Fy = ma
W - T = ma
(1000kg x 9.8 m/s² ) - 11000N = 1000 kg x a
9800 - 11000 = 1000
a = - 1.2 m/s²
Using the equation of kinematics to determine the initial velocity.
² = ² + 2ay
= √ ( 2 x 1.2m/s² x 8 m )
= √19.2 m²/s²
= 4.38 m/s ≈ 4 m/s
Hence, the initial velocity of the elevator is 4m/s.
Read more about the Equation of kinematics:
brainly.com/question/12351668
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Answer:
A) s = 796.38 m
B) t = 12.742 s
C) T = 25.484 s
Explanation:
A) First of all let's find the time it takes to get to maximum height using Newton's first equation of motion.
v = u + gt
u = 125 m/s
v = 0 m/s
g = 9.81 m/s²
Thus;
0 = 125 - 9.81(t)
g is negative because motion is against gravity. Thus;
9.81t = 125
t = 125/9.81
t = 12.742 s
Max height will be gotten from Newton's 2nd equation of motion;
s = ut + ½gt²
s = (125 × 12.742) + (½ × -9.81 × 12.742²)
s = 1592.75 - 796.37
s = 796.38 m
B) time to reach maximum height is;
t = u/g
t = 125/9.81
t = 12.742 s
C) Total time elapsed is;
T = 2u/g
T = 2 × 125/9.81
T = 25.484 s
Answer:
Car radiators: Water is used as coolant car radiators. Due to its high specific heat capacity, it can absorb a large amount of heat energy from the engine of the car, but its temperature does not rise too high.
Explanation:
i hope this answer your question if it s wrong please let know
Answer:
k = 
b = 
t = 
Solution:
As per the question:
Mass of the block, m = 1000 kg
Height, h = 10 m
Equilibrium position, x = 0.2 m
Now,
The velocity when the mass falls from a height of 10 m is given by the third eqn of motion:
where
u = initial velocity = 0
g = 10
Thus
Force on the mass is given by:
F = mg = 
Also, we know that the spring force is given by:
F = - kx
Thus
Now, to find the damping constant b, we know that:
F = - bv
Now,
Time required for the platform to get settled to 1 mm or 0.001 m is given by:
