A. True. You can use displacement to determine the volume of solids and liquids.
Answer:
1) True, 2) True, 3) False, 4) False, 5) False
Explanation:
1) True. Dissipative energy cannot be recovered, in general it is a form of heat
2) True. The dissipation can be by radiation, heat
3) False. Mechanical energy is divided into K and U but not in equal parts
4) False. When there are dissipative interactions, part of the mechanical energy is set in the form of heat, so its value decreases
5) False. Mechanical energy is the sum of those two energies
Answer:
(a). The speed of electron is
.
(b). The radius of electron is 
Explanation:
Given that,
Length = 2.5 cm
Distance = 6.0 mm
Magnetic field = 2.1 T
Potential difference = 700 V
(a). We need to calculate the electron's speed
Using formula of speed

Put the value into the formula



(b). We need to calculate the radius of electron
Using formula of centripetal force


Where,
m = mass of electron
v = speed of electron
r = radius
q = charge of electron
B = magnetic field
Put the value into the formula



Hence, (a). The speed of electron is
.
(b). The radius of electron is 4.2 cm