The model bridge captures all the structural attributes of the real bridge, at a reduced scale.
Part a.
Note that volume is proportional to the cube of length. Therefore the actual bridge will have 100^3 = 10^6 times the mass of the model bridge.
Because the model bridge weighs 50 N, the real bridge weighs
(50 N)*10^6 = 50 MN.
Part b.
The model bridge matches the structural characteristics of the actual bridge.
Therefore the real bridge will not sag either.
Answer:

Explanation:
Given that,
Heat required, Q = 1200 J
Mass of the object, m = 20 kg
The increase in temperature, 
We need to find the specific heat of the object. The heat required to raise the temperature is given by :

So, the specific heat of the object is
.
Answer:
1. 38,500
2. 308,000
Explanation:
This would require a calculator. To find momentum, you multiply mass and velocity. You always want your mass to be measure in kilograms, but that is irrelevant in this question because they already are, it is just something to remember.
Answer:
a=m/f is not an equation under newton's second law
Explanation:
newton's second law of motion is represented using: f=ma
where a=v-u/t
therefore it becomes,f=m(v-u)/t
from f=ma,
a will become f/m,
m will become f/a
This is true. The break handles and brakes are levers and the seat adjustment (raise or lower) is a screw.