All categories

4 years ago

Please help I'm desperate. and please explain how need to show work!

Physics

1 answer:

ehidna [41]4 years ago

6 0

Answer:

33.2 m/s

Explanation:

In order to solve this problem, we need to know the mass of the car.

Here, we assume that the mass of the car is

m = 1 kg

Then, we can apply the work-energy theorem, which states that the work done on the car by the braking force is equal to the change in its kinetic energy:

$W=\Delta E_k\\Fd=\frac{1}{2}mv^2-\frac{1}{2}mu^2$

where:

F = -3.87 N is the force applied by the brakes (negative because its direction is opposite to the motion of the car)

d = 4.92 m is the displacement of the car

u = 33.8 m/s is the initial velocity of the car

v is the final velocity of the car

Therefore, solving for v, we find:

$v=\sqrt{\frac{2Fd}{m}+u^2}=\sqrt{\frac{2(-3.87)(4.92)}{1}+(33.8)^2}=33.2 m/s$

You might be interested in

Which statement would most likely be found in an advertisement from a <br> cell phone provider

ki77a [65]

Answer:B

Explanation:

3 0

4 years ago

suppose that you had an ohmmeter and a mystery component that could be either an inductor or a capacitor. How could you use the

sukhopar [10]

Answer:

To determine the mystery component we will connect the mystery component to a DC voltage source, then I will measure the resistance of the component with the use of Ohmmeter, the value of the resistance of the mystery component will determine what the mystery component is

if the resistance > 1( very high ) then component is a capacitor

if the resistance = 0 then component is an inductor

Explanation:

if the resistance > 1( very high ) then component is a capacitor

if the resistance = 0 then component is an inductor

8 0

3 years ago

A neon sign that requires a voltage of 11,000 v is plugged into a 120-v wall outlet. what turns ratio (secondary/primary) must a

Arisa [49]

The equation that relates the voltages and the number of turns in a transformer is
$\frac{V_s}{V_p}= \frac{N_s}{N_p}$
where $V_s = 120 V$ is the voltage in the secondary coil, $V_p=11000 V$ is the voltage in the primary coil, and $N_s$ and $N_p$ are the number of turns on the secondary and primary coils.

Using the numbers, we find the ratio between the number of turns:
$\frac{N_s}{N_p}= \frac{V_s}{V_p}= \frac{120 V}{11000 V}=0.0109$

8 0

3 years ago

When we give the speed of a car what frame of reference are we using?

Rus_ich [418]

Frame of reference, in simplest terms, describes the state of motion of the observer. The frame of reference may also be described by using a set of coordinates, time and motion. We formulate all our equations and solve them using the frame of reference.

4 0

4 years ago

Read 2 more answers

A battery is connected to the two ends of a conducting rod and the current through it is measured.a) Another rod, made of the sa

IceJOKER [234]

Answer:

a) - the resistance is proportional to the length of the metal

- a thicker rod, since resistance decreases with increasing area

b) The current is proportional to the area so this is the factor that is influenced by the electric field

Explanation:

a) When the rod is connected to the rod an electrical circuit described by the expression is formed

V = I R

I = V / R

The resistance of the rod is

R = ρ L / A

Where ρ is the resistivity of metal, L Longitud and A cross section.

If a higher current is measured when the other rod is connected, it implies that the resistance has decreased. To have a decrease in resistance you have two possibilities

- use a shorter rod, since the resistance is proportional to the length of the metal

- Use a thicker rod, since resistance decreases with increasing area, remember that the area of a circle is

A = π R²

Therefore, small increases in the diameter of the rod could give great changes in resistance.

b) The current is defined with the charge that crosses a surface per unit of time, when the electric field increases the electrons feel a greater force, therefore the current increases.

The charge number on a wire is

Q = q n $v_{d}$ Δt A

So up to date is

I = q n When the rod is connected to the rod an electrical circuit described by the expression is formed

V = I R

I = V / R

The resistance of the rod is

R = rho L / A

Where rho is the resistivity of metal, L e; Long and A cross section.

If a higher current is measured when the other rod is connected, it implies that the resistance has decreased. To have a decrease in resistance you have two possibilities

.- use a shorter rod, since the resistance is proportional to the length of the metal

. - Use a thicker rod, since resistance decreases with increasing area, remember that the area of a circle is

A = pi R2

Therefore, small increases in the diameter of the rod could give great changes in resistance.

.b) The current is defined with the charge that crosses a surface per unit of time, when the electric field increases the electrons feel a greater force, therefore the current increases.

The load number on a wire is

Q = q n $v_{d}$ Dt A

So current is

I = q n v_{d} A

The drag speed (v_{d}) is constant in the materials, it depends on the purity and imperfections, so a change in the length does not significantly change the current.

The current is proportional to the area so this is the factor that is influenced by the electric field

The drag speed (vd) is constant in the materials, it depends on the purity and imperfections, so a change in the length does not significantly change the current.

The current is proportional to the area so this is the factor that is influenced by the electric field

8 0

3 years ago