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:
The temperature is
Explanation:
From the question ewe are told that
The rate of heat transferred is
The surface area is
The emissivity of its surface is
Generally, the rate of heat transfer is mathematically represented as
=>
where is the Boltzmann constant with value
substituting value
Answer:
<em>The centripetal acceleration would increase by a factor of 4</em>
<em>Correct choice: B.</em>
Explanation:
<u>Circular Motion</u>
The circular motion is described when an object rotates about a fixed point called center. The distance from the object to the center is the radius. There are other magnitudes in the circular motion like the angular speed, tangent speed, and centripetal acceleration. The formulas are:
If the speed is doubled and the radius is the same, then
The centripetal acceleration would increase by a factor of 4
Correct choice: B.
Answer:
b) Nothing will happen, the sea saw will still be balanced.
Explanation:
b) Nothing will happen, the sea saw will still be balanced.
Reason:-
When two kids are balanced, the sum of torques on the seesaw will be zero.
if each kid, reduces their distances by half, then the torque of each kid will be half and the sum of torque of each on the seesaw will be zero.
Therefore the seesaw is balanced
We Know, F = m.a
Here, m = 2 Kg
& a = 2 m/s²
Substitute for it,
F = 2*2 Kgm/s²
F = 4 Kgm/s²