Answer:
acceleration a= 0.1344 m/sec^2
Explanation:
Given
mass of the object m= 72 kg
Force applied with help of rope= 358 N
Acceleration due to gravity= 9.81 m/sec^2
Since there is no force acting on the person and rope
then T=F
and from the FBD we can write
2T- mg= ma ,or
2F- mg= ma
now putting the values we get
on calculating we get acceleration a= 0.1344 m/sec^2
energy is the correct answer to fill the blank bb :)
<span>When t=0, v=0, d=0
When t=tf, v=41m/s, d=3.5m
We have 2 formulas – the ones corresponding to uniformly accelerated linear movement:
vf=a*t+vo
d=(1/2)*a*t^2+vo*t
Let’s put the data in the formulas:
41m/s=a*t+0=a*t
3.5m=(1/2)*a*t^2+0*t=1/2*a*t^2
You can use a variety of methods to find t and a. I will choose substitution.
t=(41m/s)/a
3.5m=(1/2)*a*((41m/s)/a)^2=(1/2)*a*(41m/s)^2/a^2=(1/2)*(41m/s)^2/a
a=(1/2)*(41m/s)^2/(3.5m)=(1/2)*41^2(m^2/s^2)/(3.5m) a=41^2(m/s^2)/( 2*3.5)=240m/s^2</span>
Average speed = (distance covered) / (time to cover the distance)
Average speed = (1.6 km) / (30 min)
Average speed = 0.0533 km/min
This is the true average speed, but it's not in the units that the question asked for. So we have to massage it and convert it to ' meters/sec '.
Speed = (1.6 km) / (30 min)
Speed = (1.6 km / 30 min) x (1,000 m / 1 km) x (1 min / 60 sec)
Speed = (1.6 x 1,000 x 1) / (30 x 1 x 60) (km-m-min / min-km-sec)
Speed = (1,600 / 1,800) (m / sec)
<em>Speed = 0.89 m/s </em>