Can a ratio be expressed as a percentage

If the coefficient of static friction between your coffee cup and the horizontal dashboard of your car is µs = 0.800, how fast c

Cloud [144]

Answer:

Before start of slide velocity will be 14.81 m/sec

Explanation:

We have given coefficient of static friction $\mu =0.8$

Angle of inclination is equal to $\Theta =tan^{-1}\mu$

$\Theta =tan^{-1}0.8=38.65^{\circ}$

$tan{38.65^{\circ}}=0.8$

Radius is given r = 28 m

Acceleration due to gravity $g=9.8m/sec^2$

We know that $tan\Theta =\frac{v^2}{rg}$

$0.8=\frac{v^2}{28\times 9.8}$

$v^2=219.52$

$v=14.816m/sec$

So before start of slide velocity will be 14.81 m/sec

3 0

3 years ago

Sarah, who has a mass of 55 kg, is riding in a car at 20 m/s. She sees a cat crossing the street and slams on the brakes! Her se

lions [1.4K]

Answer:

-2200 N

Explanation:

Here we can use the impulse theorem, which states that the impulse exerted on Sarah (product of force and duration of collision) is equal to Sarah's change in momentum:

$I=\Delta p\\F \Delta t = m \Delta v$

where

F is the average force

$\Delta t$ is the duration of the collision

m is the mass

$\Delta v$ is the change in velocity

In this problem:

m = 55 kg

$\Delta v = 0-20 = -20 m/s$

$\Delta t = 0.5 s$

Solving the formula, we find the force exerted by the seatbelt on Sarah:

$F=\frac{m\Delta v}{\Delta t}=\frac{(55)(-20)}{0.5}=-2200 N$

And the negative sign means the direction is opposite to that of Sarah's initial motion.

6 0

3 years ago

Directions Part 2: Using what you learned about the formation of the Grand Canyon and which layer is oldest, try to answer the f

kykrilka [37]

Answer: Neighbour

Explanation: Taken perspective from the given clues:

The Neighbor walks to work

The Handyman rides a bike

The Cook rides a motorcycle

The Maid drives a car

The Nephew has a dog

If we assume that the handyman delivered the iPad in the mailbox, then

The direction of the cook, Nephew and his dog are perpendicular to the direction of the bike of the handyman. So, it can't be the cook, Nephew and the maid.

The two suspects are the handyman and the neighbour.

If the handyman actually dropped the iPad and left, then, the neighbour should be the culprit.

8 0

4 years ago

a particle of mass 1.3kg is sliding down a frictionless slope inclined at 30 to the horizontal. the acceleration of the particle

OverLord2011 [107]

Answer:

$4.9\ m/sec^2$