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Jobisdone [24]
3 years ago
6

A ball of mass 8 kg falls from rest from a height of 100 m. Neglecting air resistance,calculate its kinetic energy after falling

a distance of 30 m.
Physics
2 answers:
astra-53 [7]3 years ago
4 0
As an object falls from rest, its gravitational energy is converted to kinetic energy

G.P.E = K.E = mgh

K.E = (80 Kg)(9.8 m/s²)(30 m)

K.E. = 23,520 J
xxMikexx [17]3 years ago
3 0
At h=100m,
ME = KE + PE
ME = 1/2mv^2 + mgh
ME = 1/2m(0)^2 + mgh     Because the ball has no speed at first
ME = mgh = 8 x 9.8 x 100 = 7840 J

At h=70m   (100m-30m)
ME = KE + PE
7840 J = KE + mgh
KE = 7840 J - mgh = 7840 - 8 x 9.8 x 70
KE = 7840 - 5488
KE = 2352 J

Hope this helps

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If the coefficient of static friction between your friend and the car seat is 0.500 and you keep driving at a constant speed of
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Answer:

90m

Explanation:

Let g = 9.8 m/s2. The friction is the product of normal force and its coefficient, and normal force is equal to gravity

F_f = \mu N = \mu mg

The acceleration caused by friction, according to Newton's 2nd law:

a_f = F_f / m = \mu g = 0.5 * 9.8 = 4.9 m/s^2

For the friend to slide over, then the centripetal acceleration must be equal to friction acceleration.

Since you are driving at a constant speed of 21 m/s, then your maximum radius of curvature can be calculated using the following formula:

a_c = a_f = v^2/r = 4.9

r = v^2/4.9 = 21^2/4.9 = 90 m

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3 years ago
Newton's 2nd law describes the relation between
S_A_V [24]
It describes the relationship between force and acceleration
5 0
3 years ago
Which are the simplest pure substances that cannot be broken down into any other substances
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The simplest pure substances that cannot be broken down into any other substances are elements, such as gold (Au) or oxygen (O).
6 0
3 years ago
There is strong evidence that Europa, a satellite of Jupiter, has a liquid ocean beneath its icy surface. Many scientists think
dangina [55]

Answer:

4.44 rpm

Explanation:

\omega = Angular speed

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

r = Radius of Europa = \frac{3138000}{2}\ m

R = Radius of arm = 6 m

The acceleration due to gravity is given by

g=\frac{GM}{r^2}\\\Rightarrow g=\frac{6.67\times 10^{-11}\times 4.8\times 10^{22}}{\left(\frac{3138000}{2}\right)^2}\\\Rightarrow g=1.3\ m/s^2

Here the centripetal acceleration of the arm and acceleration due to gravity are equal

a_c=\omega^2R

a_c=g\\\Rightarrow \omega^2R=1.3\\\Rightarrow \omega^2\times 6=1.3\\\Rightarrow \omega=\sqrt{\frac{1.3}{6}}\\\Rightarrow \omega=0.46547\ rad/s

Converting to rpm

1\ rad/s=\frac{60}{2\pi}\ rpm

0.46547\ rad/s=0.46547\times \frac{60}{2\pi}\ rpm=4.44\ rpm

The angular speed of the arm is 4.44 rpm

8 0
3 years ago
The magnetic field at point P due to a 2.0-A current flowing in a long, straight, thin wire is 8.0 μT. How far is point P from t
Tanzania [10]

Answer:

r = 0.05 m = 5 cm

Explanation:

Applying ampere's law to the wire, we get:

B = \frac{\mu_oI}{2\pi r}\\\\r =  \frac{\mu_oI}{2\pi B}

where,

r = distance of point P from wire = ?

μ₀ = permeability of free space = 4π x 10⁻⁷ N/A²

I = current = 2 A

B = Magnetic Field = 8 μT = 8 x 10⁻⁶ T

Therefore,

r = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(2\ A)}{2\pi(8\ x\ 10^{-6}\ T)}\\\\

<u>r = 0.05 m = 5 cm</u>

8 0
3 years ago
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