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andrey2020 [161]

3 years ago

5

Jessica Jacob is driving down the road at 35 m/s. She sees a cop and slows to 20 m/s in only 2 seconds. What was her acceleratio

n?

1 answer:

kati45 [8]3 years ago

8 0

Answer: Acceleration = - 7.5 m/s^2

Explanation:

Acceleration (a) is the rate of change in velocity. I.e

Acceleration = (V - U)/t

U = 35 m/s

V = 20 m/a

t = 2 s

Acceleration = ( 20 - 35 )/2

Acceleration = - 15/2

Acceleration = - 7.5 m/s^2

In this case, the car is decelerating at 7.5 m/s^2

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A block rides on a piston that is moving vertically with simple harmonic motion. (a) If the SHM has period 2.68 s, at what ampli

fredd [130]

Answer:

Part a)

$A = 1.78 m$

Part b)

$f = 2 rev/s$

Explanation:

Part A)

As we know that time period of the motion is given as

$T = 2.68 s$

so we have

$\omega = \frac{2\pi}{T}$

$\omega = \frac{2\pi}{2.68}$

$\omega = 2.34 rad/s$

now at the point of maximum amplitude the force equation when Normal force is about to zero is given as

$mg = m\omega^2 A$

so we have

$A = \frac{g}{\omega^2}$

$A = \frac{9.81}{2.34^2}$

$A = 1.78 m$

Part b)

Now if the amplitude of the SHM is 6.23 cm

and now at this amplitude if object will lose the contact then in that case again we have

$mg = m\omega^2 A$

$g = \omega^2 (0.0623)$

$\omega = 12.5 rad/s$

so now we have

$2\pi f = 12.5$

$f = 2 rev/s$

3 0

3 years ago

A rock at the top of a 20 meter tall hill.The rock has a mass of 10 kg. How much potentail energy does it have?

ch4aika [34]

P.E.=mgh
= 10x10x20
=2000J

6 0

3 years ago

WHICH ROLLER COASTER CART HAS THE LEAST POTENTIAL ENERGY DUE TO GRAVITY?

DIA [1.3K]

Answer:

C. Car A

Explanation:

if the answer is: which roller coaster car has the greatest potential energy due to gravity brainly

6 0

3 years ago

Convert 68852 millijoules into Calories. (Write your answer in the decimal form. Do not include units in your answer).

alex41 [277]

Answer: 68852 millijoules = 16.46 calories

Explanation:

Given;

Convert 68852 millijoules to calories.

1 calorie = 4.184J = 4184millijoules

Therefore,

1 millijoule = 1/4184 calories

68852 millijoule = 68852 × 1/4184 calories

= 16.46 calories

6 0

3 years ago

A small space probe of mass 170 kg is launched from a spacecraft near Mars. It travels toward the surface of Mars, where it will

alukav5142 [94]

Answer:

The change in momentum is $\Delta p = kg \cdot m/s$

Explanation:

From the question we are told that

The mass of the probe is $m = 170 kg$

The location of the prob at time t = 22.9 s is $A =$

The momentum at time t = 22.9 s is $p = < 51000, -7000, 0> kg m/s$

The net force on the probe is $F = N$

Generally the change in momentum is mathematically represented as

$\Delta p = F * \Delta t$

The initial time is 22.6 s

The final time is 22.9 s

Substituting values

$\Delta p = * (22.9 - 22.6)$

$\Delta p = * (0.3)$

$\Delta p = kg \cdot m/s$

6 0

3 years ago