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3 years ago

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The measured mass of a body is found to be 110g. The length is measured by a meter scale. Actual mass and length of the body are

100 g and 10 cm. Find the percentage error in the calculation of density.

1 answer:

Elan Coil [88]3 years ago

5 0

Answer:

ok it will be g+181

Explanation:

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A wheel rotating about a fixed axis has a constant angular acceleration of 4.0 rad/s2. In a 4.0-s interval the wheel turns throu

Nady [450]

Answer:

The time interval is $t = 3 \ s$

Explanation:

From the question we are told that

The angular acceleration is $\alpha = 4.0 \ rad/s^2$

The time taken is $t = 4.0 \ s$

The angular displacement is $\theta = 80 \ radians$

The angular displacement can be represented by the second equation of motion as shown below

$\theta = w_i t + \frac{1}{2} \alpha t^2$

where $w_i$ is the initial velocity at the start of the 4 second interval

So substituting values

$80 = w_i * 4 + 0.5 * 4.0 * (4^2)$

=> $w_i = 12 \ rad/s$

Now considering this motion starting from the start point (that is rest ) we have

$w__{4.0 }} = w__{0}} + \alpha * t$

Where $w__{0}}$ is the angular velocity at rest which is zero and $w__{4}}$ is the angular velocity after 4.0 second which is calculated as 12 rad/s s

$12 = 0 + 4 t$

=> $t = 3 \ s$

4 0

2 years ago

What do you call a group of sea turtles?

Valentin [98]

Answer:

a bale

Explanation:

a bale is a group of turtles

8 0

3 years ago

Read 2 more answers

3) A driver in a 1000-kg car traveling at 24 m/s slams on the brakes and skids to a stop. If the coefticient of friction between

Natali5045456 [20]

Answer:

A) 37 m

Explanation:

The car is moving of uniformly accelerated motion, so the distance it covers can be calculated by using the following SUVAT equation:

$v^2 -u^2 = 2ad$ (1)

where

v = 0 m/s is the final velocity of the car

u = 24 m/s is the initial velocity

a is the acceleration

d is the length of the skid

We need to find the acceleration first. We know that the force responsible for the (de)celeration is the force of friction, so:

$F=ma=-\mu mg$

where

m = 1000 kg is the mass of the car

$\mu = 0.80$ is the coefficient of friction

a is the deceleration of the car

g = 9.8 m/s^2 is the acceleration due to gravity

The negative sign is due to the fact that the force of friction is against the motion of the car, so the sign of the acceleration will be negative because the car is slowing down. From this equation, we find:

$a=-\mu g$

And we can substitute it into eq.(1) to find d:

$v^2 -u^2 = 2(\-mu g) d\\d= \frac{v^2-u^2}{-2 \mu g}=\frac{0-(24 m/s)^2}{-2(0.80)(9.8 m/s^2)}=36.7 m \sim 37 m$

7 0

3 years ago

A helicopter is ascending vertically. a passenger accidentally drops her wallet out the sides of the helicopter when it is 160 m

Advocard [28]

Answer:

(E)56.0 m/s

Explanation:

Height =h=-160 m

Because the wallet moving in downward direction

Time=t=7 s

Final speed of wallet=v=0

We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.

$v^2-u^2=2gh$

Where $g=9.8 m/s^2$

Substitute the values

$0-u^2=2(-160)\times 9.8$

$u^2=3136$

$u=\sqrt{3136}=56m/s$

Option (E) is true

8 0

3 years ago

Why is the motion of an athlete moving along the circular path with Constant speed considered to be an accelerated motion?

Strike441 [17]

The speed is changing its direction all the time. There is an acceleration which changes the direction of the speed – that is called centripetal acceleration. Only uniform linear motions are considered to have no acceleration.

This is the general formula for acceleration

a = dv/dt

When calculating dv, you should keep in mind the change in the velocity vector’s direction. You can easily see in a graph that with dt tending to 0 (so the length of the arc covered is also tending to 0), the difference between vectors Vf and V0 has a direction which is perpendicular to velocity (the shorter the arc, the closest the angle is to 90 degrees).

There is a formula (which can be deducted from the previous formula) which allows you to calculate the acceleration:

a = v^2/r

Let’s talk about the units:

v is in m/s

r is in m

so v^2/r

is in (m/s)^2/m = (m^2/s^2)/m = m/s^2

which is the same unit as dv/dt:

dv/dt = (m/s)/s= m/s^2

5 0

3 years ago