A cat falls from a table of height 1.3 m. What is the impact speed of the cat?

a 25 kg object is pushed with a horizontal force of 5 N esat across a table. If the force of friction is 2 N, what is the accele

Julli [10]

Answer:

Apply Newton's second law in the moving direction.

Explanation:

$\begin{aligned}F &= ma\\5N-2N &= 25kg\times a\\a & = \frac{3N}{25kg}\\&= 0.12ms^{-2}\end{aligned}$

Friction force applies in the opposite direction of motion; as a restriction.

8 0

3 years ago

Most oxygen in our atmosphere _____. has a single oxygen atom combines with carbon has two oxygen atoms has three oxygen atoms

andrew-mc [135]

Answer:

Two oxygen atoms

Explanation:

The majority of the oxygen in the air in our atmosphere consists of molecular oxygen ( $O_2$ ), which consists of 2 atoms of oxygen, since free oxygen mainly form covalent bonds with other atoms of oxygen.

A small fraction of the oxygen, however, in the ozone form, which consists of 3 atoms of oxygen bond together ( $O_3$ ).

5 0

2 years ago

A batter hits a baseball m = 0.41 kg from rest with a force of F = 81

WITCHER [35]

Answer:

7.0s

Explanation:

Mass = 0.41kg

F= 81N

t = 0.22s

¤ = 29°

Lo = 86m

From impulse equation,

F*t = m* v

81 * 0.22 = 0.41 * v

Vo = 17.82 / 0.41

Vo = 43.46m/s

Vx= velocity across horizontal plane

Vy = velocity across vertical plane

Vx = Vo * cos ¤

Vy = Vo * sin ¤

Vx = 43.46 * cos 30° = 37.64 m/s

Vy = 43.46 sin 30° = 21.73 m/s

Distance travelled across the vertical plane,

L = Lo + Vy *t + ½gt²

0 = 86 + 21.73t - 4.9t²

4.9t² - 21.73t - 86 = 0

Solving for t in the quadratic equation,

t = 6.96 or -10.04

Using the positive root since time can't be negative, t = 6.96 approximately 7.0s

4 0

3 years ago

A small rocket with mass 20.0 kg is moving in free fall toward the earth. Air resistance can be neglected. When the rocket is 80

Mekhanik [1.2K]

Answer:

= 308.5 N

Explanation:

acceleration of rocket for safe landing

$v_{y} ^{2} = v_{0} ^{2} +2ay$

$a = \frac{v_{y}^{2} - v_{0}^{2} }{2y}$

$v_{0}$ = initial velocity

$v_{y}$ =final Velocity

m = mass of rocket

$\frac{0^{2} - 30^{2} }{2\times80}$

-5.625 $m/s^{2}$

Upward force

F - mg = ma

F = ma+ mg

F = m(a+g)

m= mass

a = 5.625 $m/s^{2}$

g = 9.8 $m/s^{2}$

= 20(5.625 $m/s^{2}$ + 9.8 $m/s^{2}$ )

= 308.5 N

7 0

3 years ago

At the instant a traffic light turns green, a car starts with a constant acceleration of 1.3 m/s2. At the same instant a truck,

Bas_tet [7]

Answer:

(a) Distance traveled = 75.3846 m

(b) Velocity of car at that instant will be 14 m/sec

Explanation:

We have given acceleration of the car $a=1.3m/sec^2$

Initial velocity of the cart u = 0 m/sec

(a) According to second equation of motion we know that $s=ut+\frac{1}{2}at^2$

So distance traveled by car $s_c=0\times t+\frac{1}{2}\times 1.3t^2=0.65t^2$

As the truck is moving with constant speed

So distance traveled by truck $s_t=ut=7t$

As the truck overtakes the car

So $s_c=s_t$

$0.65t^2=7t$

$t=10.769sec$

So distance traveled $s_c=s_t=7\times 10.769=75.3846m$

(b) From second equation of motion we know that v = u+at

So v = 0+1.3×10.769 = 14 m /sec

7 0

3 years ago