Answer:
linear density of the string = 4.46 × 10⁻⁴ kg/m
Explanation:
given,
mass of the string = 31.2 g
length of string = 0.7 m
linear density of the string = 
linear density of the string = 
linear density of the string = 44.57 × 10⁻³ kg/m
linear density of the string = 4.46 × 10⁻⁴ kg/m
Answer:

Explanation:
Impulse-Momentum relation:


We solve the equations in order to find the braking force:

Answer:
Explanation:
Let the resistance of resistor be R .
Power of resistor V² / R , where V is potential applied .
V² / R = 100
120² / R = 100
R = 120² / 100
= 144 ohm .
Now potential diff applied = 220 V
current = potential diff / resistance
= 220 / 144
= 1.53 A approx .
Uniform velocity means no Net force and therefore no acceleration. Acceleration only happens when the velocity changes.
Mass and distance
If mass is doubled, the force of gravity between the objects is doubled