Explanation:
It is given that,
Spring constant, k = 81 N/m
We need to find the force required to :
(a) Compress the spring by 6 cm i.e. x₁ = 6 cm = -0.06 m
It can be calculated using Hooke's law as :
F = - k(-x₁)

F = 4.86 N
(b) Expand the spring by 17 cm i.e. x₂ = 17 cm = +0.17 m
So, F = -kx₂

F = -13.77 N
Hence, this is the required solution.
Answer:
The mass of the water on earth is 
Explanation:
Given that,
Average depth h= 0.95 mi



Radius of earth 
Density = 1000 kg/m³
We need to calculate the area of surface
Using formula of area

Put the value into the formula


We need to calculate the volume of earth

Put the value into the formula


Now, 70 % volume of the total volume


We need to calculate the mass of the water on earth
Using formula of density


Put the value into the formula


Hence, The mass of the water on earth is 
Answer:
Option A is correct.
when it is used in a circuit. its terminal voltage will be less than 1.5 V.
Explanation:
The terminal voltage of the battery when it is in use in circuits drops lower than the 1.5 V rating given to it due to internal resistance.
All batteries give internal resistances when used in circuits. The internal resistance (though very small) is usually modelled as connected in series with the battery. It is due to some form of interference from the chemical makeup of the battery.
Normally, while the battery is fresh, the voltage (V) obtained at its terminals when connected in series with a resistor of resistance R is V = IR; where I is the current flowing in this circuit.
But once the interenal resistance (r) of the battery comes into play,
V = I₁ (r + R)
The current in the circuit evidently drops (that is I₁ < I) and V = (I₁r + I₁R)
The voltage across the terminals of the battery is no longer V but is now (V) × [R/(R+r)] which is less than the initial V and it reduces as the internal resistance, r, increases.
Hope this Helps!!!
Answer:
At the point when an item is moved into the air toward a path other than straight up or down, the speed, quickening, and uprooting of the article don't all point a similar way. In circumstances like this, when taking care of the difficult we ought to apply the procedure of settling vectors into segments. At that point we apply the more straightforward one-dimensional types of the conditions for every segment. At long last, we can recombine the parts to decide the resultant.
Explanation:
At the point when an item is moved into the air toward a path other than straight up or down, the speed, quickening, and uprooting of the article don't all point a similar way. In circumstances like this, when taking care of the difficult we ought to apply the procedure of settling vectors into segments. At that point we apply the more straightforward one-dimensional types of the conditions for every segment. At long last, we can recombine the parts to decide the resultant.
Objects that are tossed or dispatched into the air and are dependent upon gravity are called projectiles. The way of a shot is a bend called parabola. In the event that an article has an underlying speed in some random time span, there will be level movement all through the trip of the shot.
Shot movement is free fall with an underlying speed. The underlying flat speed of a shot is equivalent to the level speed all through the shot's flight.
To discover the speed go a shot anytime during its flight, discover the vector aggregate of the parts of the speed now. We should utilize the Pythagorean hypothesis to discover the extent of the speed and the digression capacity to discover the course of the speed. On the off chance that an article has an underlying vertical part of speed and a level segment of speed, the item's movement ought to be settled into its segments, and afterward the sine and cosine capacities can be utilized to locate the vertical and even segments of the underlying speed. The speed of a shot dispatched at a point to the ground has both flat and vertical parts. The vertical movement is like that of an item that is hurled straight with an underlying speed.