Answer:
Explanation:
potential energy of compressed spring
= 1/2 k d²
= 1/2 x 730 d²
= 365 d²
This energy will be given to block of mass of 1.2 kg in the form of kinetic energy .
Kinetic energy after crossing the rough patch
= 1/2 x 1.2 x 2.3²
= 3.174 J
Loss of energy
= 365 d² - 3.174
This loss is due to negative work done by frictional force
work done by friction = friction force x width of patch
= μmg d , μ = coefficient of friction , m is mass of block , d is width of patch
= .44 x 1.2 x 9.8 x .05
= .2587 J
365 d² - 3.174 = .2587
365 d² = 3.4327
d² = 3.4327 / 365
= .0094
d = .097 m
= 9.7 cm
If friction increases , loss of energy increases . so to achieve same kinetic energy , d will have to be increased so that initial energy increases so compensate increased loss .
Answer:
Explanation:
We shall first calculate the velocity at height h = 575 m .
acceleration a = 2.2 m /s²
v² = u² + 2 a s
u is initial velocity , v is final velocity , s is height achieved
v² = 0 + 2 x 2.2 x 575
v = 50.3 m /s
After 575 m , rocket moves under free fall so g will act on it downwards
If it travels further by height H
from the relation
v² = u² - 2 g H
v = 0 , u = 50.3 m /s
H = ?
0 = 50.3² - 2 x 9.8 H
H = 129.08 m
Total height attained by rocket
= 575 + 129.08
= 704.08 m .
Answer: 2200J
Explanation:
M = 44kg
V = 10m/s
K.E =?
K.E = 1/2MV2 = 1/2 x 44 x (10)^2
K.E = 22 x 100
K.E = 2200J
The answer is definitely C.) their molecules move at the same average speed
If you're holding the apple at your waist, lift it to your mouth.
Potential energy relative to any level is proportional to its height
above that level. Increase that height, and you've increased the
potential energy.
Since energy is conserved ... it never magically appears or
disappears ... you need to tell where that extra energy for the
apple came from.
It's exactly the work you did ... the force of your muscles acting
through the distance you raised the apple ... that became the
additional potential energy that the apple gained.
