The coefficient of expansion is 13 * 10^-6 m per meter length.per oK
The temperature difference = 42 - - 8 = 50 oC
delta T = (42 + 273) - (-8 + 273) = 50 oK
delta L = L * 13* 10^6 m/oK
oK = 50 oK delta L = 19.5 cm = 19.5 cm [1m / 100 cm] = 0.195m
So we need to find the length and it is computed by:
0.195= L * 13 * 10^-6 * 50 L = 0.195 / (13*10^-6*50) L = 300 m
Answer:
Hey there
Where trying to say that:
Newton's first law gives the concept of force and momentum?
That's false if that's is what you said.
Newton's first law tells us that objects in motion will remain in motion and objects at rest will remain at rest.
Newton's second law gives us the concept of force and momentum.
The weight of the box is (mass) x (gravity) = (50 kg) x (9.8m/s²) = 490 newtons.
If the box is sliding at constant speed, and not speeding up or slowing down,
that means that the horizontal forces on it add up to zero.
Since you're pushing on it with 53N in <em><u>that</u></em> direction, friction must be pulling
on it with 53N in the <u><em>other</em></u> direction.
The 53N of friction is (the weight) x (the coefficient of kinetic friction).
53N = (490N) x (coefficient).
Divide each side by 490N : Coefficient = (53N) / (490N) = 0.1082 .
Rounded to the nearest hundredth, that's <em>0.11 </em>. (choice 'd')
Direction. Velocity is a vector that describes both speed and direction, while speed is a scalar that describes only speed regardless of direction.
