Answer:
0.21m
Explanation:
Note that the 200 J before breaking legs is Kinetic energy
So if potential energy= kinetic energy
Then 200J = mgh
h= 200/75x 9.8
= 0.21m so the maximum height will be 0.21m
Answer:
Force between the two charges becomes one fourth of the initial force.
Explanation:
The electrostatic force acting between any two charges is given as,

Here,
F = force
k = Coulomb's constant
= magnitude of charge of the first particle
= magnitude of charge of the second particle
= separation between the two charges
From the above relation,
Thus,



<u>Answer</u>
A. Metals A and metals B
<u>Explanation</u>
Heat transfer takes place whenever there is temperature difference. When two bodies of different temperatures are brought together, heat energy will move from one body to the other until equilibrium temperature is reached.
In our case, heat transfer will take place in all four metals.
Metal A will transfer heat to the water since it's temperature is higher than that of water.
Metal B will also transfer heat to the water since it's temperature is higher than that of water.
Metal C will get heat from the water since it's colder than the water.
Metal D will also get heat from the water since it is colder than water.
B) 7.87 m/s
The gravitational pull is the rate of change of velocity which is the acceleration. Formula for acceleration is;

Given:
• Initial velocity = 0m/s; I dropped the ball, and didn't throw it, so it was at rest firstly
• Time taken = 2.40s
• Acceleration = 3.28m/s^2
We're require to find the final velocity, at which the ball hit the ground with. Ignoring air resistance, keep in mind that the velocity of an object increases as it comes closer to the ground.


Answer:
x(t) = -8sin2t
Explanation:
See the attachment for solution
From my solving, we can deduce that w² = 4, and thus, w = 2
Therefore, the general solution is
x(t) = c1 cos2t + c2 sin2t
Considering the final variable, we can conclude that
x(0) = 0
x'(0) = -8 m/s
The final solution, thus
x(t) = -8sin2t