Answer:
Explanation:
Let T be the tension in the swing
At top point 
where v=velocity needed to complete circular path
r=distance between point of rotation to the ball center=L+\frac{d}{2} (d=diameter of ball)
Th-resold velocity is given by 
To get the velocity at bottom conserve energy at Top and bottom
At top 
Energy at Bottom 
Comparing two as energy is conserved
Answer:
v = 30.39 m/s
Explanation:
given,
mass of glider,M = 680 Kg
mass of the skydiver, m = 68 Kg
horizontal velocity,V = 30 m/s
when skydiver releases, velocity,v = 30 m/s
velocity if the glider,v' = ?
use the conservation of momentum
M V = m' v' + m v
m' = 680-68 = 612 Kg
680 x 30 = 612 x v + 60 x 30
612 v = 18600
v = 30.39 m/s
since the skydiver's speed will be the same as before release
The glider should continue to travel at 30.39 m/s since there are no external forces acting on it
A person runs up 40 stairs and then come down 10 steps
So total stairs upwards is given as
now here we will have total height reached
Now total energy used or mechanical work done is
Now the mechanical power is given as
Required Heat = Q
Q = Mass * specific heat of water * change in temp.
Q = 5g * 1g/cal*degC * 20degC
Q = 100 cal of heat is required
To convert calories to Joules,
1 cal = 4.184 Joules
100cal = 418.4 J of heat is needed
Answer:
b
i remember this question from when i had a test to take.
