Her total distance was 200 meters, since she ran 100 meters west and the same 100 meters back. This gives an average speed of 200 m / 40 s = 5 m/s.
However, her displacement was 0, since she ended at the same place she began, therefore, her average velocity is 0 / 40 s = 0.
Answer:
Explanation:
We shall represent speed in vector form
First speed
v₁ = 1.5 cos 14 i + 1.5 sin 14 j
= 1.455 i + 0.363 j
v₂ = 4.4 cos 33 i + 4.4 sin 33 j
= 3.69 i + 2.39 j
v₂ - v₁
3.69 i + 2.39 j - 1.455 i - 0.363 j
= 2.235 i + 2.027 j
acceleration
= v₂ - v₁ / time
= ( 2.235 i + 2.027 j ) / 23
= .097 i + .088 j
force = mass x acceleration
= 398 x ( .097 i + .088 j )
= 38.6 i + 35.02 j
Magnitude of force F
F² = 38.6² + 35.02²
F = 52.11 N
Tan θ = 35.02 / 38.6
θ = 42° north of east.
The efficiency of the machine is defined as
Here
Work out is the work output and Work in is the work input
To find the Work in we have then
Replacing with our values
The work done by the applied force is
W = Fd
Here,
F = Force
d = Distnace
Rearranging to find F,
F = 129.77N
Therefore the force exerted on the machine after rounding off to two significant figures is 130N
The correct answer is A. Solid
Gas has the least density because the atoms and molecules spread to fit the container. Liquids is between solid and gas when it comes to density, while solid has the highest density due to the way the molecules are tightly and closely connected.
