Answer:
The lens to be used for the objective is lens A
Explanation:
The objective of a compound microscope
The focal length of the lens used for the objective = 1/(magnification obtained)
The focal length of most modern is equal to the tube length
The range of sizes for the focal length of a microscope is between 2 mm and 40 mm
Therefore, the appropriate lens to be used for the objective of the compound is lens A that has a focal length of 0.50 cm = 5 mm
The gravitational potential energy U is defined as the product of mass m, the acceleration of gravity g and the height of object h.

We do not have the mass of the hiker. But we know that its W weight is:

Where

So:
.
So:

J
The hiker has gained 30,000 J of energy
We can first obtain time of flight from vertical fall
Initial velocity U=0, d = 6 m, a = 9.8 m/s²
d = ut + 1/2 at²
6.0 = 0 + (1/2 × 9.80 t²)
t = √(12/9.8)
= 1.106 sec
Horizontal velocity = Vh = Dh/t
= 24.0 /1.106 s
= 21.69 m/s
The ball was thrown at a speed of 21.69 m/s
Answer:
x = -6.5 meters
Explanation:
The position of a ball as a function of time t is given by :
..................(1)
Where t is time in seconds
We need to find the position of the ball at 1.9 s. It can be simply calculated putting t = 1.9 s in equation (1) as :

x = -6.5 meters
So, the position of the ball at 1.9 seconds is -6.5 meters. Hence, this is the required solution.
Answer:
Distance is 500 m, displacement is 0
Explanation:
Distance and displacement are defined in two different ways:
- Distance is the total length of the path covered by an object in motion - so it depends on the path taken. In this problem, the distance travelled by the car corresponds to the length of one lap, which is the length of the track, so 500 m
- Displacement is the distance in a straight line between the final point and the initial point of the motion. This means that displacement does not depend on the path taken, but only on the starting and ending point of the motion. In this problem, the car completes one lap, so the final position of the car is equal to its starting position - therefore the displacement is zero, since the distance between these two points is zero.