Answer:
a) 5200 N b) 8800 N
Explanation:
a) tension in the cable when it was being lowered to the sea floor = weight of the object which acts downward ( equals the tension in the cable when the craft was stationary in opposite direction) - the drag force which will act upward = 7000 - 1800 = 5200 N
b) tension in the cable when the craft was being raised since the tension will act upward and the drag force and the weight will act downward = 7000 + 1800 = 8800 N
Answer:
(D) the sphere
Explanation:
The bodies given are Disk and Solid sphere (uniform sphere)
Moment of inertia of the bodies are
I(disk) =
I(sphere) = 
Since the moment of inertia of sphere is less than that of disk, therefore sphere will reach the bottom first.
Answer: A voltmeter must have a high resistance where as an ammeter must have a low resistance.
Explanation:
A voltmeter is a device which is connected in parallel to the component across which voltage needs to be measured. In a parallel circuit voltage drop is same at the nodes. The parallel connection must not offer easier path for current to divert from the main circuit and travel. Thus, a voltmeter must have high resistance.
On the other hand, an ammeter which is used to measure current in the circuit must have low resistance as it is connected in series. It should not offer resistance as it would reduce the actual current and measurement would be inaccurate.
Answer:
g' = 10.12m/s^2
Explanation:
In order to calculate the acceleration due to gravity at the top of the mountain, you first calculate the length of the pendulum, by using the information about the period at the sea level.
You use the following formula:
(1)
l: length of the pendulum = ?
g: acceleration due to gravity at sea level = 9.79m/s^2
T: period of the pendulum at sea level = 1.2s
You solve for l in the equation (1):

Next, you use the information about the length of the pendulum and the period at the top of the mountain, to calculate the acceleration due to gravity in such a place:

g': acceleration due to gravity at the top of the mountain
T': new period of the pendulum

The acceleration due to gravity at the top of the mountain is 10.12m/s^2
Given :
Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south.
To Find :
The magnitude and direction of
a) A + B .
b) A - B.
Solution :
Let , direction in north is given by +j and east is given by +i .
So ,
and 
Now , A + B is given by :


Direction of A+B is 45° north of west .
Also , for A-B :


Direction of A-B is 45° south of west .
( When two vector of same magnitude which are perpendicular to each other are added or subtracted the resultant is always 45° from each of them)
Hence , this is the required solution .