This point is called the epicenter. The epicenter is important when it comes to the Earth's surface, because it pinpoints where Earthquakes begin to take shape and occur. It is the place where the most damage is caused by an earthquake and is found above the hypocenter.

8 0

3 years ago

It takes 185 kj of work to accelerate a car from 23.0 m/s to 28.0 m/s. what is the car's mass?

Pachacha [2.7K]

<span>This question is based on conservation of energy as the work done would lead to change in kinetice energy of car change in KE = 1/2 mv(f)^2 - 1/2mv(i)^2 = 1/2m(v(f)^2-v(i)^2) where v(f) and v(i) are the final and initial speeds change in KE = 185kJ = 185,000J = 1/2 m((28m/s)^2-(23m/s)^2) 185,000=1/2 m(255m^2/s^2) solving for m m=1451kg</span>

6 0

3 years ago

If the briefcase hits the water 6.0 s later, what was the speed at which the helicopter was ascending?

vovikov84 [41]

Complete Question

In an action movie, the villain is rescued from the ocean by grabbing onto the ladder hanging from a helicopter. He is so intent on gripping the ladder that he lets go of his briefcase of counterfeit money when he is 130 m above the water. If the briefcase hits the water 6.0 s later, what was the speed at which the helicopter was ascending?

Answer:

The speed of the helicopter is $u = 7.73 \ m/s$

Explanation:

From the question we are told that

The height at which he let go of the brief case is h = 130 m

The time taken before the the brief case hits the water is t = 6 s

Generally the initial speed of the briefcase (Which also the speed of the helicopter )before the man let go of it is mathematically evaluated using kinematic equation as

$s = h+ u t + 0.5 gt^2$

Here s is the distance covered by the bag at sea level which is zero

$0 = 130+ u * (6) + 0.5 * (-9.8) * (6)^2$

=> $0 = 130+ u * (6) + 0.5 * (-9.8) * (6)^2$

=> $u = \frac{-130 + (0.5 * 9.8 * 6^2) }{6}$

=> $u = 7.73 \ m/s$

7 0

3 years ago