A 1-kilogram ball has 8 joules of kinetic energy.What is it speed?

Suppose a rock is dropped off a cliff with an initial speed of 0m/s. What is the rocks speed after 5 secounds, in m/s, if it enc

Tasya [4]

Answer:

The rock's speed after 5 seconds is 98 m/s.

Explanation:

A rock is dropped off a cliff.

It had an initial velocity of 0 m/s. And now it is moving downwards under the influence of gravitational force with the gravitational acceleration of 9.8 m/s².

Speed after 5 seconds = V

We know that acceleration = average speed/time

In our case,

g = ((0+V)/2)/5

9.8*5 = V/2

=> V = 2*9.8*5

V = 98 m/s

3 0

3 years ago

Read 2 more answers

Which of the following is fact-based science rather than part of a personal belief system?

marusya05 [52]

Since there are no choices, then this question calls for open-ended answers. Facts-based science must have proven underlying laws that support inferences such as Coulomb's Law, Kinetic Theory of Matter and many more. On the other hand, examples of science that focus on personal belief is philosophy. This depends on the perspective of known philosophers. An example would be Sigmund Freud who proposed the theory of 3 personalities. Although it is more on personal beliefs, this is used as a foundation in the study of psychology.

3 0

2 years ago

You are trying to find out how high you have to pitch a water balloon in order for it to burst when it hits the ground. You disc

FrozenT [24]

Answer:

The balloon hit the ground with velocity -15.34 m/s

Explanation:

Lets explain how to solve the problem

You found that the best height to pitch a water balloon in order for it to

burst when it hits the ground is 12 meters.

We consider that the 12 meters is the maximum height, so the velocity

at this height is zero.

To find the velocity when the balloon hits the ground lets use the rule

v² = u² + 2gh, where v is the final velocity, u is the initial velocity, g is

the acceleration of gravity and h is the height.

u = 0 , h = 12 m , g = 9.8 m/s²

Substitute these values in the equation above

v² = 0 + 2(9.8)(12)

v² = 235.2

Take square root for both sides

v = ± $\sqrt{235.2}$

The velocity is downward, then it's a negative value

Then v = -15.34 m/s

The balloon hit the ground with velocity -15.34 m/s

6 0

3 years ago

A worker does 25 J of work lifting a bucket, then sets the bucket back down in the same place. What is the total net work done o

Vera_Pavlovna [14]

Answer:

0 J

Explanation:

As work is force times displacement, if no displacement occurs, no work occurs.

5 0

2 years ago

An object moving at a constant speed of 25 m/s is making a turn with a radius of curvature of 7 m (this is the radius of the "ki

prisoha [69]

Answer:

- 278.34 kg m/s^2

Explanation:

The rate of the change of momentum is the same as the force.

The force that an object feels when moviming in a circular motion is given by:

F = -mrω^2

Where ω is the angular speed and r is the radius of the circumference

Aditionally, the tangential velocity of the body is given as:

v = rω

The question tells us that

v = 25 m/s

r = 7m

mv = 78 kg m/s

Therefore:

m = (78 kg m/s) / (25 m/s) = 3.12 kg

ω = (25 m/s) / (7 m) = 3.57 (1/s)

Now, we can calculate the force or rate of change of momentum:

F = - (3.12 kg) (7 m)(3.57 (1/s))^2

F = - 278.34 kg m/s^2

4 0

3 years ago