Ask question

Ask question

All categories

3 years ago

5

a 125 kg wrecking ball on a 15.4 m long cable is pulled back to an angle of 33.5 degrees and released. How much KE does it have

at the bottom of its swing? (Unit = J)

1 answer:

Nadusha1986 [10]3 years ago

3 0

Answer:

mgh = mv2/2; h = l(1 - cos33.5°); v = [2gl(1 - cos33.5°)]1/2 = 8 m/s.

We esed law of conservation of enrtgy.

Explanation:

You might be interested in

What is the coldest place on earth

exis [7]

The continent of Antartica is located at the bottom of the world. the South Pole is at its center. Antarctica is the coldest and windiest place on earth. It is covered with ice up to 3 miles thick. Very few plants and animals can survive here, but penguins, fish, and seals live on the coast and in the seas. No people live on Antarctica permanently, but scientists and tourists visit.

6 0

4 years ago

If you double the pressure on the surface of a can of water, the buoyant force on a stone placed in that water will

Bingel [31]

The buoyant force won't change.

4 0

4 years ago

A particle with charge q = 10-9 C and mass m = 5.0 x 10-9 kg is moving in a magnetic field whose magnitude is 0.003 T. The speed

Marina86 [1]

Answer:

a=0.212 m/s²

Explanation:

Given that

q= 10⁻⁹ C

m = 5 x 10⁻⁹ kg

Magnetic filed ,B= 0.003 T

Speed ,V= 500 m/s

θ= 45°

Lets take acceleration of the mass is a m/s²

The force on the charge due to magnetic filed B

F= q V B sinθ

Also F= m a ( from Newton's law)

By balancing these above two forces

m a= q V B sinθ

$a=\dfrac{qVB\ sin\theta}{m}$

$a=\dfrac{10^{-9}\times 500\times 0.003\times\ sin45^{\circ}}{5\times 10^{-9}}\ m/s^2$

$a=\dfrac{10^{-9}\times 500\times 0.003\times\dfrac{1}{\sqrt2}}{5\times 10^{-9}}\ m/s^2$

a=0.212 m/s²

4 0

4 years ago

A ball is thrown nearly vertically upward from a point near the cornice of a tall building. It just misses the cornice on the wa

vovangra [49]

Answer:

a) 48.5 ft/s

b) 36.5 ft

c) -80.3 ft/s

Explanation:

a)

The equation of motion of the ball is :

y(t) = -16.1 ft/s^2 * t^2 + Vo*t

Where Vo is the initial velocity

If y(5s) = - 160 ft:

-160 ft = -16.1 ft/s^2 * (5 s)^2 + Vo*(5s)

Solving for Vo

Vo = (16.1*25- 160) ft / 5s = 48.5 ft/s

b)

To answer this question we must first know when the velocity became zero, at this time is when the ball was at its highest point.

v(t) = -32.2 ft/s^2 * t + Vo

t = Vo/32.2ft/s^2 = 1.5 s

And now, the highest point which the ball reached is given by:

y(1.5s) = -16.1 ft/s^2 * (1.5)^2 + Vo*(1.5s)

y(1.5s) = 36.52 ft

c)

We now need the time at which y(t') = -64 ft

-64 = -16.1*t'^2 + 48.5*t'

By means of the quadratic formula, we find that

t' = 4.00498 s ≈ 4 s

And the velocity at t = 4s is:

v(4s) = -32.2 ft/s^2 * 4s +48.5 ft/s = -80.3 ft/s

3 0

4 years ago

How do physicists distinguish one type of electromagnetic wave from another?

GenaCL600 [577]

A wave is characterized by the cyclic occurrences of crests and troughs. Wavelengthis defined as the distance between two consecutive troughs or two crests and the Frequency is defined as the number of cycles that pass through a point per second

7 0

3 years ago