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VARVARA [1.3K]
2 years ago
13

A rolling ball has 18 joules of kinetic energy and is rolling 3 m/s. Find its mass.

Physics
1 answer:
SVEN [57.7K]2 years ago
7 0

Explanation:

Given: Kinetic energy K.E = 18 J; 

          Velocity = 3 m/s

Formula: K.E = 1/2 mV²

              m = 2 K.E/V²

              m = 2(18 Kg.m²/s²)/(3 m/s)²

              m = 36 Kg.m²/s²/9 m²/s²

              m = 4 Kg

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A small ball with mass 1.20 kg is mounted on one end of a rod 0.860 m long and of negligible mass. The system rotates in a horiz
Rufina [12.5K]

Answer:

0.88752 kgm²

0.02236 Nm

Explanation:

m = Mass of ball = 1.2 kg

L = Length of rod = 0.86 m

\theta = Angle = 90°

Rotational inertia is given by

I=mL^2\\\Rightarrow I=1.2\times 0.86^2\\\Rightarrow I=0.88752\ kgm^2

The rotational inertia is 0.88752 kgm²

Torque is given by

\tau=FLsin\theta\\\Rightarrow \tau=2.6\times 10^{-2}\times 0.86sin90\\\Rightarrow \tau=0.02236\ Nm

The torque is 0.02236 Nm

5 0
3 years ago
Describe an object's velocity when an acceleration-time graph is zero?
svp [43]
Anything times zero is zero
7 0
3 years ago
Read 2 more answers
If the temperature of an iron sphere is increased A)its density will decrease .B)its volume will decrease. C)its mass will decre
babymother [125]

Answer:

A) Its density will decrease

Explanation:

When an object is heated, its volume increases. This is due to the fact that the particles in the medium vibrate more (if it is a solid) or they move more (if it is a liquid or a gas), therefore they tend to occupy a larger space.

At the same time, the mass of the object does not change, because the mass just represents the amount of matter contained in the object, so it does not increase/decrease at different temperatures.

The density of an object is defined as the ratio between the mass (m) and the volume (V):

d=\frac{m}{V}

We said that the mass remains unchanged while the volume increases: since the density is inversely proportional to the volume, this means that the density decreases.

5 0
3 years ago
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An ac generator with Em = 223 V and operating at 399 Hz causes oscillations in a series RLC circuit having R = 222 Ω, L = 147 mH
Doss [256]

Answer:

Xc= 17.267 Ω,   Z= 415.5 Ω,   I= 0.537 A

Explanation:

Em = 223 V

f= 300 Hz, R = 222 Ω, L = 147 mH,  C = 23.1 μF

a)

Capacitive reactance = Xc=?

Xc= \frac{1}{2\pi fC}

Xc=1/2pi *399*23.1*10^-6

Xc= 17.267 Ω

b).

Z=\sqrt{ R^2 + (Xl - Xc)^2}

Xl= 2π * f * L  

Xl= 2π * 399 * 147 * 10^{-3}

Xl= 368.5 Ω

Z=\sqrt{ R^2 + (Xl - Xc)^2} = \sqrt{222^2 + (368.5 - 17.267)^2}

Z= 415.5 Ω  

c).

Current:

I= V / Z= Em / Z

I= 223/415.5

I= 0.537 A

3 0
3 years ago
I don't get this question could someone help out
ratelena [41]

Answer:

that would probably be Rock A is harder than Rock B

Explanation:

Because if Rock A can scratch Rock B then it obviously means that Rock A is harder.

Right?

Hope This Helps You Out♡

8 0
3 years ago
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