264 km
72 x 3 hr = 216 km
72/60 (min in an hr) = 1.2(km per min) x 40 = 48 km
216 + 48 = 264
The answer is constant acceleration.
Answer:
- solution,
- Given
- load =400N
- ld=0.2m
- ed=0.6m
- effort =150N
Explanation:
efficiency =output work/input work ×100%
l×ld/e×ed×100%
400×0.2/150×0.6×100%
80/90×100%
88.89%ans
Answer:
Explanation:
for baseball
(a) Let the mass of the baseball is m.
radius of baseball is r.
Total kinetic energy of the baseball, T = rotational kinetic energy + translational kinetic energy
T = 0.5 Iω² + 0.5 mv²
Where, I be the moment of inertia and ω be the angular speed.
ω = v/r
T = 0.5 x 2/3 mr² x v²/r² + 0.5 mv²
T = 0.83 mv²
According to the conservation of energy, the total kinetic energy at the bottom is equal to the total potential energy at the top.
m g h = 0.83 mv²
where, h be the height of the top of the hill.
9.8 x h = 0.83 x 6.8 x 6.8
h = 3.93 m
(b) Let the velocity of juice can is v'.
moment of inertia of the juice can = 1/2mr²
So, total kinetic energy
T = 0.5 x I x ω² + 0.5 mv²
T = 0.5 x 0.5 x m x r² x v²/r² + 0.5 mv²
m g h = 0.75 mv²
9.8 x 3.93 = 0.75 v²
v = 7.2 m/s
