electromagnet
When a electric current is passed through an insulated wire that is coiled around an iron core, like a nail, an electromagnet is created.
Momentum describes an object in motion and is determined by the product of two variables: mass and velocity. Mass -- the weight of an object -- is usually measured in kilograms or grams for momentum problems. Velocity is the measure of distance traveled over time and is normally reported in meters per second. Examining the possible changes in these two variables identifies the different effects momentum can have on an object in motion.
Answer:

Explanation:
Given data:
mass of sphere is 10 g
Angle between string and vertical axis is 
thickness of string 300 mm = 0.3 m

r =0.3 sin 13 = 0.067 m






q = ne


Answer:
D a thermometer
Explanation: It measures and track Celcius and Feirinheit.
Answer:
x ≤ 3.6913 m
Explanation:
Given
Mrod = 44.0 kg
L = 4.90 m
Tmax = 1450 N
Mman = 69 kg
A: left end of the rod
B: right end of the rod
x = distance from the left end to the man
If we take torques around the left end as follows
∑τ = 0 ⇒ - Wrod*(L/2) - Wman*x + T*Sin 30º*L = 0
⇒ - (Mrod*g)*(L/2) - (Mman*g)*x + Tmax*Sin 30º*L = 0
⇒ - (44*9.8)*(4.9/2) - (69*9.8)*x + (1450)*(0.5)*(4.9) = 0
⇒ x ≤ 3.6913 m