Answer:
Gravity
Explanation:
When the ball is falling to the ground, there is only one force- gravity. In some cases, there may be air resistance, but that seems to be neglected here.
Normal force:
Cannot be included. Normal force is only applicable when object is on a surface, and it acts perpendicular to the surface. Since the ball is falling, there is no surface, and therefore no normal force. This question gives you unnecessary information, designed to trick you. Please remember when normal force is applicable.
Friction force:
Also only applicable when object is moving, and is on the table. Friction only applies when there is an applied force. There is no applied force when the ball is falling, so therefore no friction force.
Force of fall:
First of all, what is this? There is nothing called force of fall.
Gravity:
This is the only one that applies. Just draw a vector arrow from the bottom of the ball and label it mg (acceleration due to gravity).
Question #1:
That's an description of an <em>parallel</em> circuit. <em>(b)</em>
Question #2:
Power = (current) x (voltage)
Power = (0.4 A) x (120 v)
Power = <em>48 watts</em>
Answer:Radiologic Dispersal Devices (RDD)
Explanation:
Radiologic Dispersal Device (RDD) is commonly known as dirty bomb. These devices require little more skill than is needed to make a conventional bomb and their components are easier to acquire. RDDs utilize conventional explosives to disperse a radioactive material packaged in the device, as opposed to a nuclear device, which creates radiation with its explosion.
Answer:
γ = 0.06563 N / m
9.78% difference
Explanation:
Solution:-
- Surface tension is the ability of any fluid to resist any external force which causes a decreases in surface area of the impact area due to inward compressive forces. These compressive forces occur due to cohesive nature of the fluid molecules.
- Mathematically, surface tension ( γ ) is defined as the force felt per unit length by the fluid.
γ = F / L
Where,
F: Force imparted
L: The length over which force is felt
- We are given the mass ( M ) of ( n = 100 ) water droplets to e 3.78 g. The mass of a single droplet ( m ) can be evaluated as follows:
m = M / n
m = 3.78 / 100
m = 0.0378 g
- The force ( F ) imparted by a single drop of water from the burette can be determined from the force balance on a single droplet. Assuming the distance over which the drop falls is negligible and resistive forces are negligible. Then the only force acting on the droplet is due to gravity:
F = m*g
F = 0.0378*9.81*10^-3
F = 0.000370818 N
- The length over which the force is felt can be magnified into a circular area with diameter equal to that of a single droplet ( d ). The circumferential length ( L ) of the droplet would be as follows:
L = π*d
L = π*( 0.0018 )
L = 0.00565 m
- Then the surface tension would be:
γ = F / L
γ = 0.000370818 / 0.00565
γ = 0.06563 N / m
- The tabulated value of water's surface tension is given as follows:
γa = 0.07275 N/m
- We will determine the percentage difference between the value evaluated and tabulated value as follows:

- The %difference between is within the allowable practical limits of 10%. Hence, the evaluated value ( γ = 0.06563 N / m ) can be accepted with 9.78% error.