Answer:If the kinetic and potential energy in a system are equal, then the potential energy increases. ... Stored energy decreases. Energy of motion decreases. Total energy decreases
Explanation:
GPE I am assuming is gravitational potential energy. I'll denote it as U for simplicity.
U = mgy
U = (70kg)(9.81m/s^2)(1m) = 686.7J
U = 686.7J
Hope this helps!
Answer: 
Explanation:
When a number is written in scientific notation (representing the number using powers of base ten) it is expressed so that it contains a digit in the place of the units and all other digits after the decimal point, multiplied by the respective exponent.
Then, the significant figures (or significant digits) will be the digits that are before the power of ten.
Now, in the case of the number 299,792,458 if we want to write it with three significant digits, we have to write it in scientific notation as:

Answer:
284.8 kgm/s
Explanation:
Impulse: This can be defined as the product of force and time of a body. The S.I unit of impulse is N.s mathematically.
Impulse = Force × time
Change in momentum: This is the product of the mass of a body and its change in velocity. The unit of change in momentum is kgm/s.
Mathematically,
momentum = mass×change in velocity
Deduction from newton's second law of motion,
Impulse = change in momentum
Therefore,
Change in Momentum = Force×time
ΔM = F×t................. Equation 1
Where F = force = 89 N, t =time = 3.2 s.
Substitute into equation 1
ΔM = 89×3.2
ΔM = 284.8 kgm/s
Thus the change in momentum = 284.8 kgm/s