It takes an average of 8 minutes and 20 seconds.
Answer:
Explanation:
Let the velocity after the 4 gram pencil strikes is v .
kinetic energy of the combination = 1/2 m v²
= .5 x ( 4 + 221 ) x 10⁻³ x v² = work done by friction
friction force acting on the combination = 225 x10⁻³x .325 x 9.8 = .7166 N
work done by friction
= .7166 x .119 = .085 J
.5 x 225 x 10⁻³ v² = .085
v² = .085 / .1125 = .7555
v = .8692 m = 86.92 cm /s
Velocity of combination after collision = 86.92 cm /s
Let velocity of pencil before collision be V
Applying law of conservation of momentum at the time of collision ,
4 x V = 225 x 86.92
V = 4889.25 cm / s
= 48.9 m /s .
It is True because hitting your head 20 time will cause problems
Answer:
Velocity
Explanation:
Kinetic Energy of a body can be defined as the amount work needed to accelerate a body of mass, m, from a position of rest to a particular velocity.
It is also the energy possessed by a body due to its motion.
Mathematically, it is given as:

As seen from the formula, the Kinetic energy is dependent on the mass of the body, m, and the square of the velocity, v.
Typically, the mass of an object is a constant value, hence, the kinetic energy varies as velocity varies.