Answer:
10 seconds
Explanation:
x = x₀ + v₀ t + ½ at²
250 = 0 + (0) t + ½ (5) t²
250 = 2.5 t²
t² = 100
t = 10
It takes 10 seconds to land from a height of 250 ft.
Answer:
a)30.14 rad/s2
b)43.5 rad/s
c)60633 J
d)42 kW
e)84 kW
Explanation:
If we treat the propeller is a slender rod, then its moments of inertia is

a. The angular acceleration is Torque divided by moments of inertia:

b. 5 revolution would be equals to
rad, or 31.4 rad. Since the engine just got started


c. Work done during the first 5 revolution would be torque times angular displacement:

d. The time it takes to spin the first 5 revolutions is

The average power output is work per unit time
or 42 kW
e.The instantaneous power at the instant of 5 rev would be Torque times angular speed at that time:
or 84 kW
Answer:
410.4J
Explanation:
Step one:
given
mass= 3.35kg
weight= 3.35*9.81= 32.86N
h=12.49m
Required
The net work done
Step two:
the work done is given as
WD= force* distance
WD= 32.86*12.49
WD= 410.4J
Answer:
He is warmed up now
Explanation:
His muscles are better and stretched now