Explanation:
Work = Force x Displacement
Force = Weight of student
Weight = Mass x Acceleration due to gravity
Mass, m = 80 kg
Acceleration due to gravity, g = 9.81 m/s²
Weight = 80 x 9.81 = 784.8 N
Displacement = 8 m
Work = 784.8 x 8 = 6278.4 J
The amount of work done by the student to elevate his body to this height is 6278.4 J
Power is the ratio of work to time taken
Power is 523.2 Watts
Answer: There will be 75258 nuclei left at 6 pm.
Explanation:
a) half-life of the radioactive substance:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time for decomposition = 6 hours ( from 12 noon to 6 pm)
A = activity at time t = ?
= initial activity = 600, 000
Thus there will be 75258 nuclei left at 6 pm.
Answer:
The lighter frog goes higher than the heavier frog.
The lighter frog is moving faster than the heavier frog
Explanation:
If both frogs have the same kinetic energy when they leave the ground, the following equality applies:
Now, if the only force acting on the frogs is gravity, when they reach to the maximum height, we can apply the following kinematic equation:
When h= hmax, the object comes momentarily to an stop, so vf =0
Solving for hmax:
As the lighter frog, in order to have the same kinetic energy than the heavier one, has a greater initial velocity, it will go higher than the other.
As a consequence of both having the same kinetic energy, the lighter frog will be moving faster than the heavier frog.
Answer:
The value is
Explanation:
From the question we are told that
The Coulomb constant is
The charge on the electron/proton is
The mass of proton
The mass of electron is
Generally for the electron to be held up by the force gravity
Then
Electric force on the electron = The gravitational Force
i.e
Answer:
<u>The flux decreases because the angle between B⃗ and the coil's axis changes.</u>
<u />
Explanation:
The flux through the coil is given by a dot product, between the magnetic field and the vector representing the area of the coil.
The latter vector has direction perpendicular to the plane in which the area of the coil is, and magnitude equal to the area of the coil. As in the attached image, the vector S is the vector respresenting the area of the coil.
Therefore, the flux will be maximum when the vector S is in the same direction as B, and will be zero when they are perpendicular.
Now, if <em>the coil is rotated so that the magnetic field is in the plane of the coil </em>then, the vectors S and B are perpendicualr, and there will not be net magnetic flux, that is, the flux will decrease.
