A race car makes one lap around a track of radius 50m in 90sec. what is the average velocity?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff ideal sprin

shepuryov [24]

Answer:

The magnitude of force must you apply to hold the platform in this position = 888.89 N

Explanation:

Given that :

Workdone (W) = 80.0 J

length x = 0.180 m

The equation for this work done by the spring is expressed as:

$W = \frac{1}{2}k_{eq}x^2$

Making the spring constant $k_{eq}$ the subject of the formula; we have:

$k_{eq} = \frac{2W}{x^2}$

Substituting our given values, we have:

$k_{eq} = \frac{2*80}{0.180^2}$

$k_{eq} = 4938.27 \ N.m^{-1}$

The magnitude of the force that must be apply to the hold platform in this position is given by the formula :

$F = k_{eq}x$

$F = 4938.27*0.180$

F = 888.89 N

6 0

3 years ago

The driver of a car traveling at a speed of 27 m/s slams on the brakes and comes to a stop in 3 s. If we assume that the speed c

NISA [10]

Answer:

Average speed = 13.5 m/s

Explanation:

Since the car is running at a speed of 27 m/s and it stops after 3 seconds by applying the brake. Therefore, the initial speed of the 27 m/s and final speed is 0.

Use below formula to find the average speed :

Average speed = (Initial speed + final speed ) / 2

Average speed = (27 + 0 ) / 2

Average speed = 13.5 m/s

7 0

3 years ago

Please help me with 1,2,3,4,5,6

Trava [24]

I know that 4. Is wave 2 and 5. Is wave 3.

3 0

3 years ago

A 16 g rifle bullet traveling 240 m/s buries itself in a 3.6 kg pendulum hanging on a 2.5 m long string, which makes the pendulu

iren [92.7K]

Answer:

x = 0.54 m

y = 0.058 m

Explanation:

m = mass of the bullet = 16 g = 0.016 kg

v = speed of bullet before collision = 240 m/s

M = mass of the pendulum = 3.6 kg

L = length of the string = 2.5 m

h = height gained by the pendulum after collision

V = speed of the bullet and pendulum combination

Using conservation of momentum

m v = (m + M) V

(0.016) (240) = (0.016 + 3.6) V

V = 1.062 m/s

Using conservation of energy

Potential energy gained by bullet and pendulum combination = Kinetic energy of bullet and pendulum combination

(m + M) g h = (0.5) (m + M) V²

(9.8) h = (0.5) (1.062)²

h = 0.058 m

y = vertical displacement = h = 0.058 m

x = horizontal displacement

horizontal displacement is given as

x = sqrt(L² - (L - h)²)

x = sqrt(2.5² - (2.5 - 0.058)²)

x = 0.54 m

8 0

3 years ago

Spitting cobras can defend themselves by squeezing muscles around their venom glands to squirt venom at an attacker. Suppose a s

Alenkasestr [34]

Answer: 1.289 m

Explanation:

The path the cobra's venom follows since it is spitted until it hits the ground, is described by a parabola. Hence, the equations for parabolic motion (which has two components) can be applied to solve this problem:

<u>x-component: </u>

$x=V_{o}cos\theta t$ (1)

Where:

$x$ is the horizontal distance traveled by the venom

$V_{o}=3.10 m/s$ is the venom's initial speed

$\theta=47\°$ is the angle

$t$ is the time since the venom is spitted until it hits the ground

<u>y-component: </u>

$y=y_{o}+V_{o}sin\theta t+\frac{gt^{2}}{2}$ (2)

Where:

$y_{o}=0.44 m$ is the initial height of the venom

$y=0$ is the final height of the venom (when it finally hits the ground)

$g=-9.8m/s^{2}$ is the acceleration due gravity

Let's begin with (2) to find the time it takes the complete path:

$0=0.44 m+3.10 m/s sin\theta(47\°)+\frac{-9.8m/s^{2} t^{2}}{2}$ (3)

Rewritting (3):

$-4.9 m/s^{2} t^{2} + 2.267 m/s t + 0.44 m=0$ (4)

This is a quadratic equation (also called equation of the second degree) of the form $at^{2}+bt+c=0$ , which can be solved with the following formula: