Answer:
-4.0 N
Explanation:
Since the force of friction is the only force acting on the box, according to Newton's second law its magnitude must be equal to the product between mass (m) and acceleration (a):
(1)
We can find the mass of the box from its weight: in fact, since the weight is W = 50.0 N, its mass will be
And we can fidn the acceleration by using the formula:
where
v = 0 is the final velocity
u = 1.75 m/s is the initial velocity
t = 2.25 s is the time the box needs to stop
Substituting, we find
(the acceleration is negative since it is opposite to the motion, so it is a deceleration)
Therefore, substituting into eq.(1) we find the force of friction:
Where the negative sign means the direction of the force is opposite to the motion of the box.
The answer is parallel
If the <span>circuits in a car</span> were series, they would go out at the same time.
I hope this helps! :3
Answer:
0.231 N
Explanation:
To get from rest to angular speed of 6.37 rad/s within 9.87s, the angular acceleration of the rod must be
If the rod is rotating about a perpendicular axis at one of its end, then it's momentum inertia must be:
According to Newton 2nd law, the torque required to exert on this rod to achieve such angular acceleration is
So the force acting on the other end to generate this torque mush be:
Answer:
a) The maximum potential difference the wet human body can take = 5.88 V
b) This value is very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.
This means one should be very careful operating electrical appliances (even at home) while the body is wet.
Explanation:
From Ohm's law, V = IR
The resistance of the body when the body is wet = 1.2 kΩ = 1200 Ω
Maximum safe current that the body can withstand = 4.90 mA = 0.0049 A
Maximum voltage the body can withstand while wet = (Maximum safe current that the body can withstand) × (Resistance of the body when the body is wet) = 0.0049 × 1200 = 5.88 V
b) This value is still very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.
This means one should be very careful operating electrical appliances (even at home) while the body is wet.
I believe the answer is B)
Hope this helps*
