Answer:
mass of the earth is directly proportional to its gravity and the radius is inversely proportional to its gravity. ... But when you go inside the surface of the earth inspiteof decreasing radius the force of gravity decreases.
Explanation:
Answer:
Explanation:
Given
angular velocity 
Combined moment of inertia of stool,student and bricks 
Now student pull off his hands so as to increase its speed to suppose 
rev/s
After Pulling off hands so final moment of inertia is
Conserving angular momentum as no external torque is applied
That's the period of time known as one solar "day". We subdivide it into 24 slices which we call "hours". Using this system of time units, the day is about 4 minutes longer than one complete axial rotation of the Earth.
Answer:
. Doppler ultrasound is based on absorption of sound, and other
ultrasound technology is based on reflection.D.
Explanation:
Answer:
hmax = 1/2 · v²/g
Explanation:
Hi there!
Due to the conservation of energy and since there is no dissipative force (like friction) all the kinetic energy (KE) of the ball has to be converted into gravitational potential energy (PE) when the ball comes to stop.
KE = PE
Where KE is the initial kinetic energy and PE is the final potential energy.
The kinetic energy of the ball is calculated as follows:
KE = 1/2 · m · v²
Where:
m = mass of the ball
v = velocity.
The potential energy is calculated as follows:
PE = m · g · h
Where:
m = mass of the ball.
g = acceleration due to gravity (known value: 9.81 m/s²).
h = height.
At the maximum height, the potential energy is equal to the initial kinetic energy because the energy is conserved, i.e, all the kinetic energy was converted into potential energy (there was no energy dissipation as heat because there was no friction). Then:
PE = KE
m · g · hmax = 1/2 · m · v²
Solving for hmax:
hmax = 1/2 · v² / g
