The initial mechanical energy is the potential energy (PE) which can be solved through the equation,
PE = mgh = (40 kg)(9.8 m/s²)(12 m) = 4,704 J
The energy at the bottom is the kinetic energy and can be calculated through the equation,
KE = 0.5mv² = (0.5)(40 kg)(10 m/s)² = 2000 J
Therefore, she lost 2,704 J of energy due to friction
By using the radiometric age dating
Answer:
Explanation:
Let the charge on the ball bearing is q.
charge on glass bead, Q = 20 nC = 20 x 10^-9 C
Force between them, F = 0.018 N
Distance between them, d = 1 cm = 0.01 m
By use of Coulomb's law in electrostatics
By substituting the values
Thus, the charge on the ball bearing is
Answer: 1224 joules
Explanation:
Given variables are:
Power (p) = 68 W
Time taken (t) = 18 seconds
work done (w) = ?
Recall that power is the rate of work done per unit time i.e Power is obtained by dividing the work done by the time taken.
Hence, Power = work / time
Make work the subject formula
work = power x time
work = 68 watts x 18 seconds
work = 1224 joules
Thus, 1224 joules of work is done.