Which of the following is contact force

What determines velocity rather than speed??

Stella [2.4K]

Velocity - the speed of something in a given direction
Speed - rapidity in moving, going, traveling, proceeding, or performing; swiftness; celerity
Velocity is the speed in a certain direction, whereas speed is just the rate of fastness.
Does that make sense?

3 0

3 years ago

A force of 960 newtons stretches a spring 4 meters. A mass of 60 kilograms is attached to the end of the spring and is initially

Drupady [299]

Answer:

x(t) = - 6 cos 2t

Explanation:

Force of spring = - kx

k= spring constant

x= distance traveled by compressing

But force = mass × acceleration

==> Force = m × d²x/dt²

===> md²x/dt² = -kx

==> md²x/dt² + kx=0 ------------------------(1)

Now Again, by Hook's law

Force = -kx

==> 960=-k × 400

==> -k =960 /4 =240 N/m

ignoring -ve sign k= 240 N/m

Put given data in eq (1)

We get

60d²x/dt² + 240x=0

==> d²x/dt² + 4x=0

General solution for this differential eq is;

x(t) = A cos 2t + B sin 2t ------------------------(2)

Now initially

position of mass spring

at time = 0 sec

x (0) = 0 m

initial velocity v= = dx/dt= 6m/s

from (2) we have;

dx/dt= -2Asin 2t +2B cost 2t = v(t) --- (3)

put t =0 and dx/dt = v(0) = -6 we get;

-2A sin 2(0)+2Bcos(0) =-6

==> 2B = -6

B= -3

Putting B = 3 in eq (2) and ignoring first term (because it is not possible to find value of A with given initial conditions) - we get

x(t) = - 6 cos 2t

==>

4 0

3 years ago

You have a spring-loaded air rifle. When it is loaded, the spring is compressed 0.3 m and has a spring constant of 150 N/m. In j

Feliz [49]

The potential energy of the spring is 6.75 J

The elastic potential energy stored in the spring is given by the equation:

$E= \frac{1}{2} kx^2$

where;

k is the spring constant

x is the compression/stretching of the string

In this problem, we have the spring as follows:

k = 150 N/m is the spring constant

x = 0.3 m is the compression

Substituting in the equation, we get

$E=\frac{1}{2} (150) (0.3)^2$

$E=6.75J$

Therefore. the elastic potential energy stored in the spring is 6.75J .

Learn more about potential energy here:

brainly.com/question/10770261

#SPJ4

6 0

1 year ago

7. An object can be accelerating even if its speed is

steposvetlana [31]

Answer:

I think that the answer might be d

4 0

2 years ago

Read 2 more answers

Estimate how long it took King Kong to fall straight down from the top of the Empire State Building (380 m high). Express your a

ankoles [38]

Answer:

It will take 8.80 sec to fall from the building

Explanation:

We have given height pf the state building h = 380 m

Initial velocity will be 0 m /sec

So u = 0 m/sec

Acceleration due to gravity $g=9.8m/sec^2$

We have to find the fall time

According to second equation of motion $h=ut+\frac{1}{2}gt^2$

So $380=0\times t+\frac{1}{2}\times 9.8\times t^2$

$t^2=77.55$

t = 8.80 sec

3 0

3 years ago