Answer:

Explanation:
We'll use the momentum equation:

where:
p = momentum
m = mass
v = velocity
Since we're doing the magnitude of momentum of the system, we'll add the mass of the cyclist and the mountain bike together:

Given that, we can now substitute our given values into the momentum equation:

Our final answer is:

Burning, in general, is a chemical change.
Why?
This is because we are breaking and/or forming new bonds. We form a totally different substance.
Answer:0.4 m
Explanation:
Given
Maximum displacement A=0.49
The sum of kinetic and elastic potential energy is 
where k=spring constant
U+K.E.=
when K.E.=U/2
K.E.=kinetic energy
U=Elastic potential Energy

Answer:
The density of the metal is 5200 kg/m³.
Explanation:
Given that,
Weight in air= 0.10400 N
Weight in water = 0.08400 N
We need to calculate the density of metal
Let
be the density of metal and
be the density of water is 1000kg/m³.
V is volume of solid.
The weight of metal in air is



.....(I)
The weight of metal in water is
Using buoyancy force


We know that,
....(I)
Put the value of
in equation (I)

Put the value of Vg in equation (II)



Hence, The density of the metal is 5200 kg/m³.