Answer:
The mass of Laura and the sled combined is 887.5 kg
Explanation:
The total force due to weight of Laura and friction on the sled can be calculated as follows;
= (400 + 310) N
= 710 N
From Newton's second law of motion, "the rate of change of momentum is directly proportional to the applied force.
where;
is mass of Laura and
is mass of sled
Mass of Laura and the sled combined is calculated as follows;
given
V = Δv = 4-0 = 4m/s
t = 5 s
Therefore, the mass of Laura and the sled combined is 887.5 kg
The impulse is (force) x (time) = (20 N) x (20 sec) = 400 N-sec
When we grind through the units, we find that the [newton-second]
is exactly the same as the [kilogram-meter/sec] unit-wise, and once
we know that, it doesn't surprise us to learn that impulse is equivalent
to a change in momentum (mass x speed ... also kg-m/s).
So this impulse exerted on the moving object adds 400 kg-m/s of
linear momentum to its motion, directed to the right. That may or
may not be the total change in its momentum during that 20-sec,
because our 20-N may not be the only force acting on it.
C)Electric Charges Produce Electric Fields
D, a<span>s a sound source moves away from a stationary object, the sound waves. It is the opposite of what happens. </span>
Examples of devices that convert electrical energy into mechanical energy — in other words, devices that use electrical energy to move something — include:
the motor in today’s standard power drills
the motor in today’s standard power saws
the motor in an electric tooth brushes
the engine of an electric car
the motor in a fan
the motor in a remote control cars that runs on batteries. So your answer would be B. Motorsport
