An imbalance of electrons causes an object to be charged. A charged substance is one that has a net charge that is not zero. If the number of protons and that of electrons is equal in an object, the object is not neutral, but it has zero charge. Loss or gain of electrons determine the charge of an object, when an object loses electrons it becomes positively charged, but when it gains electrons it becomes negatively charged.
Answer:
Sonia's grandfather was not able to see clearly after returning from his walk on a bright sunny day. He was about to hit a chair when Sonia held him and guided him to the nearby sofa, in sunny environment grandfather's eye is set according to high brightness, his pupils become small to lower the number of light rays entering his eye, when he returned from sunny environment to his house which was having low brightness so the pupils should enlarge to absorb more light to see clearly but due to old age his Ciliary muscle of the eye would have worn out and due to this poor coordination the image was not clear.
If all the energy she put into bending the bow is completely
transmitted to the arrow, then the arrow has the 100 joules
of kinetic energy when it leaves the bow.
Kinetic energy = (1/2) (mass) (speed)²
100 J = (1/2) (0.5 kg) (speed²)
Divide each side by 0.25 kg: 100 J / 0.25 kg = speed²
[ joule ] = [ newton-meter ] = kg-m²/sec²
100 kg-m²/sec² / 0.25 kg = speed²
400 m²/sec² = speed²
Take the square root of each side: speed = √400 m/s
20 m/s
(about 44.7 mph)
Answer:
21.59 m/s
Explanation:
recall that one of the equations of motions can be expressed as
v² = u² + 2as
where,
v = final velocity (we are asked to find this)
u = initial velocity = 0m/s (because it says that it starts from rest)
a = acceleration = 3.7m/s²
s = distance travelled = 63 m
simply substitute the known values above into the equation:
v² = u² + 2as
v² = 0² + 2(3.7)(63)
v² = 466.2
v = √466.2
v = 21.59 m/s
