Answer: 2.21 m/s
Explanation:
Given
Coin reaches a height of 0.25 m above the launch point
Suppose u is the initial speed of the coin
Using the equation of motion

Putting values

Thus, the initial velocity is 2.21 m/s
Answer:
V at C is 3.6 m/s
Explanation:
At A kinetic energy is zero and potential energy=mgh=0.5*9.81*0.6=2.943 J
By conservation of energy.
KE+PE=Constant
At C PE=0.6 J
the KE=2.943-0.6=2.343 J
KE=0.5*m*v^2
v=√[KE/(0.5*m)]=3.06 m/s
So, there should be two forces acting on the refrigerator: the applied force and the friction force.
The question mentioned that the friction force was set to zero, so the only effective force now would be the applied force.
We have an applied force of 400 N to the right, this means that:
<span>The magnitude of the net force is 400, directed to the right.</span>
Answer:
We show added energy to a system as +Q or -W
Explanation:
The first law of thermodynamics states that, in an isolated system, energy can neither be created nor be destroyed;
Energy is added to the internal energy of a system as either work energy or heat energy as follows;
ΔU = Q - W
Therefore, when energy is added as heat energy to a system, we show the energy as positive Q (+Q), when energy is added to the system in the form of work, we show the energy as minus W (-W).
Answer
given,
length of bar = 80 cm
mass of the bar = 10 kg
smaller mass = 4 kg
distance = 20 cm


taking moment about B






difference between two scale = 8 - 6
= 2 N