Answer:
43.3 s
Explanation:
At the maximum height, the velocity is 0 m/s.
Given:
v₀ = 424 m/s
v = 0 m/s
a = -9.8 m/s²
Find: t
v = at + v₀
0 = -9.8t + 424
t ≈ 43.3
The time is approximately 43.3 seconds.
Answer:
By convention a negative torque leads to clockwise rotation and a positive torque leads to counterclockwise rotation.
here weight of the child =21kgx9.8m/s2 = 205.8N
the torque exerted by the child Tc = - (1.8)(205.8) = -370.44N-m ,negative sign is inserted because this torque is clockwise and is therefore negative by convention.
torque exerted by adult Ta = 3(151) = 453N , counterclockwise torque.
net torque Tnet = -370.44+453 =82.56N , which is positive means counterclockwise rotation.
b) Ta = 2.5x151 = 377.5N-m
Tnet = -370.44+377.5 = 7.06N-m , positive ,counterclockwise rotation.
c)Ta = 2x151 = 302N-m
Tnet = -370.44+302 = -68.44N-m, negative,clockwise rotation.
Answer:
Explanation:
All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis.for example when we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun. We can think of this energy as having been deposited in a natural solar power bank over millions of years.
So, in one sense, gasoline-burning cars, coal-burning power plants, and homes heated by natural gas are all solar powered!
Answer:
a) 
b) 
c) Towards the center of the centrifuge
Explanation:
a)
Becuse the centrifuge rotates in circular motion, there's an angular acceleration tha simulates high gravity accelerations

with r the radius and ω the amgular velocity, in or case
so:
and g=9.8
solving for ω:


b) Linear speed (v) and angular speed are related by:


c) The apparent weigth is pointing towards the center of the circle, becuse angular acceleration is pointing in that direction.
Answer: The riders are subjected to 11.5 revolutions per minute
Explanation: Please see the attachments below