Hi I need help with my work can you help me please
Answer:
v = 1.08 m/s
Explanation:
What is the linear speed of the 0.0500-kg sphere as its passes through its lowest point?
The decrease in PE is
d = 80.0cm * 1 / 1000m = 0.80m
h = 0.80 m /2 = 0.40 m
ΔPE = m*g*h
ΔPE = (0.0500 - 0.0200)kg * 9.8m/s² * 0.400 m
ΔPE = 0.1176 J
The moment of inertia of the assembly is
I = 1/12*m*L² + (m1 + m2)*(L/2)²
I = 1/12*0.390kg*(0.800m)² + 0.0700kg*(0.400m)²
I = 0.032 kg·m²
KE = ½Iω²
0.1176 J = ½ * 0.032kg·m² * ω²
ω = 2.71 rad/s
v = ωr = 2.71 rad/s * 0.400m
The linear velocity
v = 1.08 m/s
The efficiency of a heat engine is given by the expression 
The efficiency of a heat engine is the ratio of the work done by the engine to the heat given as the input to the engine.
The heat engine absorbs Q h from the hot reservoir , performs a work <em>W</em> on the absorbed heat and rejects Qc to the cold reservoir.
Therefore, the work done is given by,
Thus the efficiency is given by,
Answer: option 4: A wire that is 2-mm thick and coiled.
Explanation:
The current in each wire is same. The magnetic field due to a current carrying wire increases if the wire is coiled with the more number of turns. A thick wire would cause low resistance to the current. Hence, a 2-mm thick wire which is coiled would produce the strongest magnetic field.
Answer:
2.5 kg
Explanation:
We can solve the problem by using Newton's second law:
where
F is the net force acting on the train
m is the mass of the train
a is the acceleration
For the toy train in the problem,
F = 3.0 N
a = 1.2 m/s^2
So we can solve the formula for m, to find the mass of the train:
