Im not going to lie, this is a physics Q right here<br> plz guys im being serious i need help

A car slows down from speed of 72

Nastasia [14]

Explanation:

Given parameters:

Initial velocity = 72km/hr

Final velocity = 0km/hr

Time taken = 25s

Unknown:

Acceleration = ?

Solution:

To solve this problem, convert km/hr to m/s;

1000m = 1km

3600s = 1hr

72km/hr;

1km/hr = 0.278m/s

72km/hr = 0.278 x 72 = 20.02m/s

Acceleration is the change in velocity divided by the time taken;

Acceleration = $\frac{final velocity - initial velocity }{time}$

Acceleration = $\frac{0 - 20.02}{25}$ = -0.8m/s

The car is actually decelerating at a rate of 0.8m/s

5 0

3 years ago

In 1.71 minutes, a ski lift raises four skiers at constant speed to a height of 148 m. The average mass of each skier is 62.9 kg

Vitek1552 [10]

Answer:

3560.36 Watts

Explanation:

Power, $P=\frac {nΔW}{Δt)$ where P is power, n is the number of skiers, t is time in seconds and Δt is change in time, ΔW is given by mgh where m is mass, g is gravitational constant, h is height

Substituting n for 4 skiers, m for 62.9 Kg, g for 9.81, h for 148 m and t for 1.71*60=102.6 seconds

P= $\frac {4*62.9*9.81*148}{1.71*60}=3560.360702 Watts$

Average power is approximately 3560.36 Watts

6 0

4 years ago

A. A light wave moves through glass (n=1.5) at an angle of 25°. What angle will it have when it moves from the glass into air (n

torisob [31]

PART A)

By Snell's law we know that

$n_1sin i = n_2 sin r$

here we know that

$n_1 = 1.5$

$i = 25 degree$

$n_2 = 1$

now from above equation we have

$1.5 sin25 = 1 sin r$

$r = 39.3 degree$

so it will refract by angle 39.3 degree

PART B)

Here as we can see that image formed on the other side of lens

So it is a real and inverted image

Also we can see that size of image is lesser than the size of object here

Here we can use concave mirror to form same type of real and inverted image

PART C)

As per the mirror formula we know that

$\frac{1}{d_i} + \frac{1}{d_o} = \frac{1}{f}$

$\frac{1}{d_i} + \frac{1}{60} = \frac{1}{20}$

$d_i = 30 cm$

so image will form at 30 cm from mirror

it is virtual image and smaller in size

3 0

4 years ago

In a series lrc circuit, the frequency at which the circuit is at resonance is f0. If you double the resistance, the inductance,

taurus [48]

When you double capacitance and inductance, the new resonance frequency becomes f/2.

Resonance frequency:

The resonance frequency of RLC series circuit, is the frequency at which the capacity reactance is equal to inductive reactance.

It can also be defined as the natural frequency of an object where it tends to vibrate at a higher amplitude.

Xc = Xl

which gives the value for resonance frequency:

$f = \frac{1}{2\pi \sqrt{LC} }$

where;

f is the resonance frequency

L is the inductance

C is the capacitance

When you double capacitance and inductance, the new resonance frequency becomes;

$f' = \frac{1}{2\pi \sqrt{2L2C} }$

$f' = \frac{1}{2\pi \sqrt{4LC} }$

$f' = \frac{1}{\pi \sqrt{LC} }\frac{1}{2}$

$f' = \frac{1}{2} f$

Thus from above,

When you double capacitance and inductance, the new resonance frequency becomes f/2.

Learn more about resonance frequency here:

<u>brainly.com/question/13040523</u>

#SPJ4

6 0

2 years ago

James rode his bike 0.65 hours and traveled 8.45 km. What was his speed?

maria [59]

Speed = (distance covered) / (time to cover the distance)

= ( 8.45 km) / (0.65 hr)

= (8.45 / 0.65) km/hr

= 13 km/hr

5 0

4 years ago

Im not going to lie, this is a physics Q right here plz guys im being serious i need help