This table shows the weights of four different objects that are sitting on the

Two objects of equal mass collide on a horizontal frictionless surface. Before the collision, object A is at rest while object B

fenix001 [56]

Answer: 6m/s

Explanation:

Using the law of conservation of momentum, the change in momentum of the bodies before collision is equal to the change in momentum after collision.

After collision, the two objects will move at the same velocity (v).

Let mA and mB be the mass of the two objects

uA and uB be their velocities before collision.

v be their velocity after collision

Since the two objects has the same mass, mA= mB= m

Also since object A is at rest, its velocity = 0m/s

Velocity of object B = 12m/s

Mathematically,

mAuA + mBuB = (mA+mB )v

m(0) + m(12) = (m+m)v

0+12m = (2m)v

12m = 2mv

12 = 2v

v = 6m/s

Therefore the speed of the composite body (A B) after the collision is 6m/s

7 0

4 years ago

2. Kevin works as a janitor, and he is pushing a fully-

dybincka [34]

The time taken for him to move the bin 6.5 m is 2.30 s.

The given parameters;

weight of the load, w = 557 N
force applied , F = 410 N
angle of force, = 15°
coefficient of kinetic friction = 0.46
distance moved, d = 6.5 m

The net horizontal force on the recycling bin is calculated as follows;

$Fcos\theta - F_k = ma$

where;

m is the mass of the recycling bin
$F_k$ is the frictional force

W = mg

$557 = 9.8m\\\\m = \frac{557}{9.8} \\\\m = 56.84 \ kg$

The net horizontal force on the recycling bin is calculated as;

$Fcos \theta - F_k = ma\\\\Fcos\theta - \mu_kF_n = ma\\\\410\times cos(15) \ - \ 0.46(557) = 56.84 a\\\\139.8 = 56.84a\\\\a = \frac{139.8}{56.84} \\\\a = 2.46 \ m/s^2$

The time taken for him to move the bin 6.5 m is calculated as follows;

$s = v_0t + \frac{1}{2} at^2\\\\6.5 = 0 + \frac{1}{2} \times 2.46\times t^2\\\\6.5 = 1.23 t^2\\\\t^2 = \frac{6.5 }{1.23} \\\\t^2 = 5.285\\\\t = \sqrt{5.285} \\\\t = 2.30 \ s$

Thus, the time taken for him to move the bin 6.5 m is 2.30 s.

Learn more here:brainly.com/question/21684583

7 0

3 years ago

On a cross-country trip, a couple drives 500 mi in 10 h on the first day, 380 mi in 8.0 h on the second day, and 600 mi in 15 h

Zepler [3.9K]

We know that the average speed is simply the ratio of the total distance travelled over the total duration of the trip.

total distance = 500 mi + 380 mi + 600 mi

total distance = 1,480 mi

total time = 10 h + 8 h + 15 h

total time = 33 h

So the average speed is therefore:

average speed = 1,480 mi / 33 h

average speed = 44.85 mi / h

8 0

3 years ago

How does the frequency of infrared electromagnetic waves compare with the frequency of radio and microwaves?

iVinArrow [24]

Answer:

Answer is B.

Because the wavelength of infrared is shorter than microwave radiation

8 0

3 years ago

Explain the relationship between the earth's crust and the earth's ocean sizes.

valina [46]

the outermost layer of Earth’s lithosphere that is found under the oceans and molded at scattering centres ono ceanic ridges, which occur at deviating plate boundaries

Oceanic crust is about 6 km (4 miles) thick.

hope it helps

3 0

3 years ago