Answer:
3136
Explanation:
because you multiply 780 by 4 because if it has a constant speed meaning it will not change speed then you multiply it by 4 because it says in 4 hours ( I hope this helped)
Answer:
8.6 m/s
Explanation:
We can find the final velocity of the dog by using the following SUVAT equation:

where
u is the initial velocity
a is the acceleration
d is the distance covered
For the dog in the problem, we have
u = 1.5 m/s

And the distance covered is
d = 3.0 m
Therefore, we can re-arrange the equation to find the final velocity, v:

The answer is b.) the momentum before the collision is greater than the momentum after the collision
Answer:
The lethal voltage for the electrician under those conditions is 126.5 V.
Explanation:
To discover what is the lethal voltage to the electrician we need to find out what is the voltage that produces 55 mA = 0.055 A when across a resistance of 2300 Ohms (Electrician's body resistancy). For that we'll use Ohm's Law wich is expressed by the following equation:
V = i*R
Where V is the voltage we want to find out, i is the current wich is lethal to the electrician and R is his body resistance. By applying the given values we have:
V = 0.055*2300 = 126.5 V.
The lethal voltage for the electrician under those conditions is 126.5 V.