Answer:

Given:
Mass (m) = 3.0 kg
Uniform speed (v) = 20 m/s
Length of string (r) = 40 cm = 0.4 m
To Find:
Tension in the string (T)
Explanation:
Tension (T) is the string will be equal to centripetal force (
).

Substituting value of m, v & r in the equation:


Tension in the string (T) = 3 kN
Answer:
P = 4.5 watts
Explanation:
Given that,
EMF of the circuit, E = 3 volt
The resistance of the resistors, R = 2 ohms
We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :

Substitute all the values,

So, the power of this circuit is equal to 4.5 watts.
Answer:
Weight of the dog on surface of earth is 140.14 Newton.
Given:
mass of the dog = 14.3 kg
To find:
Weight of the dog = ?
Formula used:
Weight of the dog is given by,
W = mg
Where, W = weight of the dog
m = mass of the dog
g = acceleration due to gravity
Solution:
Weight of the dog is given by,
W = mg
Where, W = weight of the dog
m = mass of the dog = 14.3 kg
g = acceleration due to gravity
W = 14.3 × 9.8
W = 140.14 Newton
Weight of the dog on surface of earth is 140.14 Newton.