<span>A motor produces less mechanical energy than the energy it uses because the motor looses some energy to heat.</span>
Answer:
(a) 62.5 m
(b) 7.14 s
Explanation:
initial speed, u = 35 m/s
g = 9.8 m/s^2
(a) Let the rocket raises upto height h and at maximum height the speed is zero.
Use third equation of motion


h = 62.5 m
Thus, the rocket goes upto a height of 62.5 m.
(b) Let the rocket takes time t to reach to maximum height.
By use of first equation of motion
v = u + at
0 = 35 - 9.8 t
t = 3.57 s
The total time spent by the rocket in air = 2 t = 2 x 3.57 = 7.14 second.
Answer:
The needed energy to melt of ice is 1670 J.
Explanation:
Given that,
Mass of ice = 5 g
Specific latent heat = 334000 J/kg
We need to calculate the energy
Using formula of energy

Where, m = mass
L = latent heat
Put the value into the formula


Hence, The needed energy to melt of ice is 1670 J.
As I found out the choices for your question which are:
<span>A) F2 to F-
B) Cr2O7²- → Cr2+
C) O2 to H2O
D) HAsO2 to As
</span>
Unfortunately, the answer does not belong to the choices provided. In fact, it is the oxidation half-reaction that occurs at the anode of an electrode for it to transform chemical energy to consumable electrical energy.