Answer:
Magnets can create electricity and electricity can create a magnetic force.
Both electric charges and magnets do not have to touch an object in order to exert a force on it.
Electromagnets use electricity to create a magnetic force.
Explanation:
Answer:
D. Calculate the area under the graph.
Explanation:
The distance made during a particular period of time is calculated as (distance in m) = (velocity in m/s) * (time in s)
You can think of such a calculation as determining the area of a rectangle whose sides are velocity and time period. If you make the time period very very small, the rectangle will become a narrow "bar" - a bar with height determined by the average velocity during that corresponding short period of time. The area is, again, the distance made during that time. Now, you can cover the entire area under the curve using such narrow bars. Their areas adds up, approximately, to the total distance made over the entire span of motion. From this you can already see why the answer D is the correct one.
Going even further, one can make the rectangular bars arbitrarily narrow and cover the area under the curve with more and more of these. In fact, in the limit, this is something called a Riemann sum and leads to the definition of the Riemann integral. Using calculus, the area under a curve (hence the distance in this case) can be calculated precisely, under certain existence criteria.
Answer:
ΔF=125.22 %
Explanation:
We know that drag force on the car given as
=Drag coefficient
A=Projected area
v=Velocity
ρ=Density
All other quantity are constant so we can say that drag force and velocity can be given as
Now by putting the values
Percentage Change in the drag force
ΔF=125.22 %
Therefore force will increase by 125.22 %.
The second circuit with 4.5 A current has more resistance.
Explanation:
potential difference= 6 V
resistance of first circuit=0.80 Ω
for second circuit, current= i=4.5 A
using Ohm's law V= i R
6=4.5 R
R=1.33 Ω
So the second circuit has a greater resistance.
Answer:
9.8 m/s
Explanation:
The work done by the force pushing the cart is equal to the kinetic energy gained by the cart:
where
W is the work done
is the final kinetic energy of the cart
is the initial kinetic energy of the cart, which is zero because the cart starts from rest, so we can write:
But the work is equal to the product between the pushing force F and the displacement, so
So, the final kinetic energy of the cart is 480 J. The formula for the kinetic energy is
(1)
where m is the mass of the cart and v its final speed.
We can find the mass because we know the weight of the cart, 98.0 N:
Therefore, we can now re-arrange eq.(1) to find the final speed of the cart:
