Answer:
80 min
Explanation:
Distance = rate × time
280 Cal = 3.5 Cal/min × t
t = 80 min
Answer:
3.125 m
Explanation:
We are given that
Mass of box=m=11.2 kg
Speed of box=u=3.5m/s
Coefficient of kinetic friction=
Final velocity,v=0
a.We have to find the horizontal force applied by worker to maintain the motion.
According to question
Horizontal force=F=

Substitute the values
Horizontal force=
b.According to work-energy theorem






Hence, the box slide before coming to rest=3.125 m
Answer:
Ф = 239.73 rad
Explanation:
α = 12 + 15×t
W = ∫α×dt
= ∫(12 + 5×t)×dt
= 12×t + 2.5×t^2
then:
Ф = ∫W×dt
= ∫(12×t + 2.5×t^2)dt
= 6×t^2 + 5/6×t^3
therefore the angle at t = 4.88s is:
Ф = 6×(4.88)^2 + 5/6×(4.88)^3
= 239.73 rad
Answer:
kinetic energy=1/2mv^2.
which is 4320000=1/2×m×23^2.
which is 4320000=1/2×m×529.
4320000=264.5m.
m=4320000/264.5.
m=16332.70~16333g