You have written the answer within your question.
mass of 1kg metal is "1 kilogram"
but when you talk about it's weight
then,
it's weight is 9.8 Newton.
The particle has constant acceleration according to

Its velocity at time
is



Then the particle has position at time
according to


At at the point (3, 6, 9), i.e. when
, it has speed 8, so that

We know that at some time
, the particle is at the point (5, 2, 7), which tells us

and in particular we see that

and

Then



That is, there are two possible initial velocities for which the particle can travel between (3, 6, 9) and (5, 2, 7) with the given acceleration vector and given that it starts with a speed of 8. Then there are two possible solutions for its position vector; one of them is

First figure shows the object position
Second shows the image position
Third shows the focal length.
Answer:
increase in temperature of water is 10° C
Explanation:
Given data
pizza = 500 kcal = 500000 calories
cold water = 50 L
to find out
increase in temperature of water
solution
we know heat formula that is
heat = m × specific heat × Δt
here m is mass = 50000 gram and Δt is change in temperature
and specific heat = 1 cal / gram C
so put here all value and find Δt
500000 = 50000 × 1 × Δt
Δt = 10° C
so increase in temperature of water is 10° C