Answer:
h=15.27m
Explanation:
Since at maximum height the vertical velocity must be null it's better to use the formula:

We will use this formula for the vertical direction, choosing the upward direction as the positive one, so we have:

or

which for our values is:

Buoyant force is the force that is a result from the pressure exerted by a fluid on the object. We calculate this value by using the Archimedes principle where it says that the upward buoyant force that is being exerted to a body that is immersed in the fluid is equal to the fluid's weight that the object has displaced. Buoyant force always acts opposing the direction of weight. We calculate as follows:
Fb = W
Fb = mass (acceleration due to gravity)
Fb = 64.0 kg ( 9.81 m/s^2)
Fb = 627.84 kg m/s^2
Therefore, the buoyant force that is exerted on the diver in the sea water would be 627.84 N
Answer: C)The yellow car was faster. Yellow traveled at a speed of 50 mph while green was traveling at an average of 40 mph.
Explanation:
The speed of each car is defined as:

where d is the distance traveled by the car and t is the time taken.
For the yellow car, d=400 mi and t=8 h, so its speed is

For the green car, d=400 mi and t=10 h, so its speed is

So, the correct choice is
C)The yellow car was faster. Yellow traveled at a speed of 50 mph while green was traveling at an average of 40 mph.
This question is based on the fundamental assumption of vector direction.
A vector is a physical quantity which has magnitude as well direction for its complete specification.
The magnitude of a physical quantity is simply a numerical number .Hence it can not be negative.
A negative vector is a vector which comes into existence when it is opposite to our assumed direction with respect to any other vector. For instance, the vector is taken positive if it is along + X axis and negative if it is along - X axis.
As per the first option it is given that a vector is negative if its magnitude is greater than 1. It is not correct as magnitude play no role in it.
The second option tells that the magnitude of the vector is less than 1. Magnitude can not be negative. So this is also wrong.
Third one tells that a vector is negative if its displacement is along north. It does not give any detail information about the negativity of a vector.
In a general sense we assume that vertically downward motion is negative and vertically upward is positive. In case of a falling object the motion is vertically downward. So the velocity of that object is negative .
So last option is partially correct as the vector can be negative depending on our choice of co-ordinate system.
Answer:
a. 7.046 Nm²/C
b. 2.348 Nm²/C
Explanation:
Data given:
Base of equilateral triangle = 25.0 cm = 0.25 m
Strength of electric field = 260 N/C
In order to find the electric flux we first have to find out the area of triangle.
Area of triangle = 
= 
= 0.0271 m³
Lets find electric flux,
Electric Flux = E. A
= 260×0.0271
= 7.046 Nm²/C
Now we can find the electric flux through each of the three sides.
Electric flux through three sides = 
= 2.348 N m²/C