All categories

4 years ago

An object's reflection in a plane mirror appears to be 30 m away. How far is the real object from the mirror?

1 answer:

5 0

30 m away.the image is the same distance behind the mirror as the object is in front of it. if stand a 5m away from the mirror then ur image will also be 5m behind the mirror.

You might be interested in

He conducted experiments in combining elements

Wewaii [24]

Where is the rest .........

3 0

3 years ago

The speed limit on certain interstate highways is 60 miles per hour.

nevsk [136]

Answer:

A.88 feet per second.

B.96.56 km /hr

Explanation:

When converting from miles per hour to feet per second, we can use the following conversion factor.

1 mile per hour = 1.46667 feet per second.

Hence, 60 miles per hour will be = 60 X 1.46667 = 88 feet per second.

Similarly, we can use the same process when converting from miles per hour to km per second.

1 mile = 1.60934 km

hence to convert we will multiply 60 miles/hour by 1.60934 km = 96.56 km /hr

7 0

3 years ago

A coil lies flat on a level tabletop in a region where the magnetic field vector points straight up. The magnetic field suddenly

Inessa [10]

Answer:

c. Clockwise

Explanation:

As per FARADAY's the rate of change in magnetic flux linked with a coil will induce EMF in the coil and this will result the induce current in the coil.

Here we know that the direction of induced current in the closed loop is in such a way that the magnetic flux due to induced current always oppose the flux due to which it is induced

So we can say that if the flux linked with the coil will increase with time then flux of induced current will be in opposite direction to oppose the increasing flux.

So here when magnetic field becomes stronger then the induced current is in such a way that will always oppose the increasing flux of magnetic field

So we will say that correct answer will be

c. Clockwise

5 0

3 years ago

A ballast is dropped from a stationary hot-air balloon that is at an altitude of 576 ft. Find (a) an expression for the altitude

Nadya [2.5K]

Answer:

Explanation:

If a ball dropped from a stationary hot-air balloon that is at an altitude of 576 ft, an expression for the altitude of the ballast after t seconds can be expressed using the equation of motion;

$S = ut + \frac{1}{2}at^{2}$

S is the altitude of the ballest

u is the initial velocity

a is the acceleration of the body

t is the time taken to strike the ground

Since the body is dropped from a stationary air balloon, the initial velocity u will be zero i.e u = 0m/s

Also, since the ballast is dropped from a stationary hot-air balloon, the body is under the influence of gravity, the acceleration will become acceleration due to gravity i.e a = +g

Substituting this values into the equation of the motion;

$S = 0 + \frac{1}{2}gt^2\\ S = \frac{1}{2}gt^2\\$

a) An expression for the altitude of the ballast after t seconds is therefore

$S = \frac{1}{2}gt^2\\$

b) Given S = 576ft and g = 32ft/s², substituting this into the formula in (a);

$576 = \frac{1}{2}(32)t^2\\\\\\576*2 = 32t^2\\1152 = 32t^2\\t^2 = \frac{1152}{32} \\t^2 = 36\\t = \sqrt{36}\\ t = 6.0secs$

This means that the ballast strikes the ground after 6secs

c) To get the velocity when it strikes the ground, we will use the equation of motion v = u + gt.

v = 0 + 32(6)

v = 192ft

7 0

4 years ago

A coil has N turns enclosing an area of A. In a physics laboratory experiment, the coil is rotated during the time interval delt

zmey [24]

Answer:

a) Magnetic flux before the plane is rotated = (BA) Wb

b) Magnetic flux after the plane is rotated = 0 Wb

c) Magnitude of the average induced emf =

(NBA)/Δt

Explanation:

The magnetic flux is given as

Φ = BA cos θ

where B = magnetic field strength

A = Cross sectional Area of the loop enclosed

θ = the angle in the equation above is between the line normal to plane (NOT the plane itself!) and the magnetic field.

a) Given that the position of the plane of each turn is perpendicular to Earth's magnetic field before being rotated.

Before the plane is rotated, θ = 0°

Φ = BA cos θ = BA cos 0° = BA

b) Given that the position of the plane of each turn is parallel to Earth's magnetic field after being rotated.

After the plane is rotated, θ = 90°

Φ = BA cos θ = BA cos 90° = 0

c) According to the Faraday's law of electromagnetic induction,

E = - N (ΔΦ/Δt) (minus sign to indicate that the direction of the induced emf is opposite the direction of the change of magnetic flux)

ΔΦ = (final Φ) - (initial Φ) = (0 - BA) = - BA

E = - N (- BA)/Δt

E = (NBA)/Δt

Hope this Helps!!!

8 0

3 years ago

Read 2 more answers