The third choice.
The driver wants to see the object that is behind him. The light reflects off the mirror into the eyes of the driver portraying the object behind him
Answer:
option (a) 0.61 s
Explanation:
Given;
Time taken by the ball to reach the ground = 0.50 s
Let us first calculate the distance through which the ball falls on the ground
from the Newton's equation of motion, we have

where,
s is the distance
a is the acceleration
t is the time
here it is the case of free fall
thus, a = g = acceleration due to gravity
u = initial speed of the ball = 0
on substituting the values, we get

or
s = 1.225 m
Now,
when the elevator is moving up with speed of 1.0 m/s
the initial speed of the ball = -1.0 m/s (as the elevator is moving in upward direction)
thus , we have

or

or
4.9t^2 - t - 1.225 = 0
or
t = 0.612 s
hence, the correct answer is option (a) 0.61 s
The Average velocity for the bacterium is 0.75 unit/sec.
<u>Explanation:</u>
The given values are in the vector form
Where,
dS = distance covered
dT = time interval
Now, to calculate distance covered, we have

&

d S=(4.6 i+1.9 k)-(2.2 i+3.7 j - 1.2 k)
d S=(4.6-2.2) i+(0-3.7) j+(1.9+1.2) k
d S=2.4 i-3.7 j+3.1 k
Now, putting these values in the standard formula to evaluate the average velocity, we get;


As dT=7.2 sec
Now,
Solving the equation, we get;


Hence, the average velocity for the bacterium is 0.75 unit/sec.
Answer:
The cup with 0.5L
Explanation:
To know what amount of water you take into account the specific heat of the water. The specific heat of water is:

Thus, 4186 J of energy are needed to icrease the temperature of 1 kg water in 1°C. Then, more grams of water will need more energy.
You have that one cup has 0.5 L and the other one has 750mL = 0.75L
The second cup of water will need more heat because the amount of water contained in the second cup is greater than in the first cup with 0.5L