Answer:
Two identical closely spaced circular disks form a parallel-plate capacitor. Transferring 2.1×109 electrons from one disk to the other causes the electric field strength between them to be 1.6×105 N/C. What are the diameters of the disks?
Explanation:
Check attachment for solution
As per the question Bob drops the bag full with feathers from the top of the building.
The mass of the bag(m)= 1.0 lb
Let the air resistance is neglected.As the bag is under free fall ,hence the only force that acts on the bag is the force of gravity which is in vertical downward direction.
Here the acceleration produced on bag due to the free fall will be nothing else except the acceleration due to gravity i.e g =9.8 m/s^2
Here we are asked to calculate the distance travelled by the bag at the instant 1.5 s
Hence time t= 1.5 s
From equation of kinematics we know that -
S=ut + 0.5at^2 [ here S is the distance travelled]
For motion under free fall initial velocity (u)=0.
Hence S= 0×1.5+{0.5×(-9.8)×(1.5)^2}
⇒ -S =0-11.025 m
⇒ S= 11.025 m
=11 m
Here the negative sign is taken only due to the vertical downward motion of the body .we may take is positive depending on our frame of reference .
Hence the correct option is B.
"If one increases the force on an object, its acceleration increases too because the push it feels is greater"
We have the 2nd law of Newton that relates the 3 concepts; F=m*a. We have that if the mass of an object increases (put weight in luggage), the accelearation decreases; in fact it is inversely proportional to the mass. Hence if the mass is doubled, acceleration is halved. Accelerations is proportional to force; if one doubles the force, the acceleration doubles too.
1000 kcal because you only get 10% of the energy of the thing you eat
Answer:
57.6Joules
Explanation:
Rotational kinetic energy of a body can be determined using the expression
Rotational kinetic energy = 1/2Iω²where;
I is the moment of inertia around axis of rotation. = 5kgm/s²
ω is the angular velocity = ?
Note that torque (T) = I¶ where;
¶ is the angular acceleration.
I is the moment of inertia
¶ = T/I
¶ = 3.0/5.0
¶ = 0.6rad/s²
Angular acceleration (¶) = ∆ω/∆t
∆ω = ¶∆t
ω = 0.6×8
ω = 4.8rad/s
Therefore, rotational kinetic energy = 1/2×5×4.8²
= 5×4.8×2.4
= 57.6Joules