Answer:
63 m
Explanation:
Average speed of swimming = 45 m/min
Time = 1 minute 24 seconds
Converting time into minutes:
Formula:
Putting values, we get.
Thus, Alex swims for 63 m in 1 minute and 24 seconds.
Answer:Velocity can be represented by an arrow, with the length of the arrow representing speed and the way the arrow points representing direction. Objects have the same velocity only if they are moving at the same speed and in the same direction. ... The SI unit for velocity is m/s, plus the direction the object is traveling.
It is B since they are traveling at the same speed one is positive so the other had to be negative hope this helps;)))))
Answer:
(a) 
(b) 
(c) K.E. = 21.168 J
(d) 
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,

- constant downward acceleration,

That a constant upward acceleration of
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,



∴Work by the cord on the block,


We take -ve sign because the direction of force and the displacement are opposite to each other.

(b)
Force on the block due to gravity:

∵the gravity is naturally a constant and we cannot change it


∴Work by the gravity on the block,



(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:


K.E. = 21.168 J
(d)
From the equation of motion:

putting the respective values:

is the speed when the block has fallen 4.2 meters.