Answer:
Approximately 
.
Assumption: the ball dropped with no initial velocity, and that the air resistance on this ball is negligible.
Explanation:
Assume the air resistance on the ball is negligible. Because of gravity, the ball should accelerate downwards at a constant 
near the surface of the earth.
For an object that is accelerating constantly,
,
where
is the initial velocity of the object,
is the final velocity of the object.
is its acceleration, and
is its displacement.
In this case, is the same as the change in the ball's height: 
. By assumption, this ball was dropped with no initial velocity. As a result, 
. Since the ball is accelerating due to gravity, 
.
.
In this case, would be the velocity of the ball just before it hits the ground. Solve for
.
.
Answer: the loop will move up
Explanation:
Whenever an electric current cuts across magnetic field lines, a force is exerted on the current - carrying conductor
According to Fleming's left hand rule, the thumb is the direction of motion.
First finger is the direction of magnetic field, while the second finger is the direction of the conventional current.
When a current flow in the will, the wire will experience an upward force. And continue to rotate in an up - down direction. Therefore, the loop will move up.
Answer:
A) 0.120
B) 1.6s
C) 0.625 Hz
Explanation:
Here, X = 0.120 m
x = 0.120 m after t = 0.800 s
A- Amplitude = max displacement from equillibrium position = 0.120 m
B- Period = 2 * 0.800 = 1.6 s
C- Frequency = 1/peroid = 1/1.6
f = 0.625 Hz
Answer:
6.23×10^(14) particles
Explanation:
Let the total power be P_0
now according to question
5% ×P_0=30W
so P_0=30/0,05=600 W.
an alpha particle'energy is 5.5 MeV
Let n be number of alpha particles emitted per sec.
Therefore,
n=600J/5.5MeV=600/(5.5×e^6×1.6×e^-19)=6.82×e^14(particles)
