Answer:
A) 89.39 J
B) 30.39J
C) 23.8 J
Explanation:
We are given;
F = 30.2N
m = 3.5 kg
μ_k = 0.646
d = 2.96m
ΔEth (Block) = 35.2J
A) Work done by the applied force on the block-floor system is given as;
W = F•d
Thus, W = 30.2 x 2.96 = 89.39 J
B) Total thermal energy dissipated by the whole system which includes the floor and the block is given as;
ΔEth = μ_k•mgd
Thus, ΔEth = 0.646 x 3.5 x 9.8 x 2.96 = 65.59J
Now, we are given the thermal energy of the block which is ΔEth (Block) = 35.2J.
Thus,
ΔEth = ΔEth (Block) + ΔEth (floor)
Thus,
ΔEth (floor) = ΔEth - ΔEth (Block)
ΔEth (floor) = 65.59J - 35.2J = 30.39J
C) The total work done is considered as the sum of the thermal energy dissipated as heat and the kinetic energy of the block. Thus;
W = K + ΔEth
Therefore;
K = W - ΔEth
K = 89.39 - 65.59 = 23.8J
Velocity is defined as a change in position.
For an object`s motion, the Kinematic equation is,
Here, v is the final velocity and h is stands for the height of the object and a is the acceleration of the object.
As according to question,
and 
Thus, putting these values in above equation, we get
or
Therefore, initial velocity is 2.8 m/s
In the circuit, the total current is 60 A and the voltage is 240 V. If R1
resistance is 20 Ω, then the R2 resistance would be 5 Ω
<h3>What is resistance?</h3>
Resistance is the obstruction of electrons in an electrically conducting material. The SI unit of the resistance is Ohm
The mathematical relation for resistance can be understood with the help of the empirical relation provided by Ohm's law.
V=IR
where V is the voltage
I is the current
R is the resistance
For the given problem V= 240 V and I = 60 A
R = V/I
R =240/60
R =4 Ω
For calculating equivalent resistance in parallel combination.
1/Re = 1/R1 + 1/R2
1/4 = 1/20 + 1/R2
R2 = 5 Ω
Thus , the R2 resistance would be 5 Ω, therefore the correct answer is option B.
Learn more about resistance here
brainly.com/question/14547003
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