Answer:
v = 8.63 m/s
Explanation:
Neglecting the frictional forces, the law of conservation of energy can be applied to this situation as follows:
Potential Energy Gained By Athlete = Kinetic Energy Lost By Athlete
mgh = (0.5)mv²
gh = (0.5)v²
v = √2gh
where,
v = speed that the athlete must have when he plants the pole = ?
g = acceleration due to gravity = 9.8 m/s²
h = Height to be achieved by the athlete = 3.8 m
Therefore,
v = √(2)(9.8 m/s²)(3.8 m)
<u>v = 8.63 m/s</u>
Answer:
Explanation:
Let mass of bullet = m1 = 28g= 0.028 kg
mass of pendulum = m2 = 3.1 kg
A) The average translational kinetic energy of the molecules in a gas is given by:
where
is the Boltzmann's constant
T is the absolute temperature of the gas
In our problem,
, so the average translational kinetic energy of the molecules is
We have 1.2 mol of this gas, and since one mole of ideal gas contains a number of molecules equal to Avogadro number, the total number of molecules in our gas is
So the total translational kinetic energy of all molecules of the gas is
B) The kinetic energy of a person is given by:
where m is the person's mass and v his velocity. The person has a mass of m=75 kg and its energy is equal to the energy of the gas,
, therefore his velocity must be
Answer:
Th-234, Pa-234
Explanation:
In alpha decay, 2 protons and 2 neutrons are lost. So U-238 would become Th-234.
In beta decay, one neutron is turned into a proton. So Th-234 would become Pa-234.