Explanation:
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Answer:
Explanation: simple kinematics
we suppose that initially vo= 0 so if the skier moves 4s :
vf = vo +at = 0 + 3*4 = 12 m/s
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Answer:
The minimum coefficient of friction is 0.27.
Explanation:
To solve this problem, start with identifying the forces at play here. First, the bug staying on the rotating turntable will be subject to the centripetal force constantly acting toward the center of the turntable (in absence of which the bug would leave the turntable in a straight line). Second, there is the force of friction due to which the bug can stick to the table. The friction force acts as an intermediary to enable the centripetal acceleration to happen.
Centripetal force is written as

with v the linear velocity and r the radius of the turntable. We are not given v, but we can write it as

with ω denoting the angular velocity, which we are given. With that, the above becomes:

Now, the friction force must be at least as much (in magnitude) as Fc. The coefficient (static) of friction μ must be large enough. How large?

Let's plug in the numbers. The angular velocity should be in radians per second. We are given rev/min, which can be easily transformed by a factor 2pi/60:

and so 45 rev/min = 4.71 rad/s.

A static coefficient of friction of at least be 0.27 must be present for the bug to continue enjoying the ride on the turntable.
Answer:
The mass of the banana is m and it is at height h.
Applying the Law of Conservation of Energy
Total Energy before fall = Total Energy after fall
=
Here, total energy is the sum of kinetic energy and potential energy
+
=
+
(a)
When banana is at height h, it has
= 0 and
= mgh
and when it reaches the river, it has
= 1/2m
and
= 0
Putting the values in equation (a)
0 + mgh = 1/2m
+ 0
mgh = 1/2m
<em>cutting 'm' from both sides</em>
<em> </em>gh = 1/2
v = 
Hence, the velocity of banana before hitting the water is
v = 