Problem 18 if anyone could help that would be amazing!

Suppose a cheetah running at a velocity of 5 m/s east slows down. After 15 seconds, the cheetah has reached a velocity of 25 m/s

Darina [25.2K]

Answer:

1.33m/s²

Explanation:

Given parameters:

Initial velocity = 5m/s

Final velocity = 25m/s

Time taken = 15seconds

Unknown:

Acceleration = ?

Solution:

Acceleration is the rate of change of velocity with time.

Acceleration = $\frac{v - u}{t}$

v is the final velocity

u is the initial velocity

t is the time taken

So;

Acceleration = $\frac{25 - 5}{15}$ = 1.33m/s²

5 0

3 years ago

Which is a disadvantage of using wind as an energy source?

lesantik [10]

Answer:

it produces

Explanation:

a lot of waste

5 0

3 years ago

Read 2 more answers

Jacki evaluated the expression below. 2 cubed (3 minus 1) + 4 (8 minus 12) = 2 cubed (2) + 4 (4) = 8 (2) + 16 = 16 + 16 = 32. Wh

Naddika [18.5K]

Answer:

Her error was that she did not subtract 12 from 8 correctly

Explanation:

Jackie did 8-12 instead of 12-8

8 0

3 years ago

Glider A of mass 2.5 kg moves with speed 1.7 m/s on a horizontal rail without friction. It collides elastically with glider B of

omeli [17]

Answer:

The speed of glider A after the collision is 0 m/s

Explanation:

Hi there!

The two gliders collide elastically. That means that the kinetic energy and momentum of the system are conserved, i.e., they remain constant before and after the collision.

The momentum is calculated as follows:

p = m · v

Where:

p = momentum.

m = mass.

v = velocity.

The equation of kinetic energy is the following:

KE = 1/2 · m · v²

Where:

KE = kinetic energy.

m = mass.

v = velocity.

The momentum of the system is the sum of the momentum of each glider.

be:

mA = mass of glider A

mB = mass of glider B

vA = velocity of glider A before the collision.

vB = velocity of glider B before the collision.

vA´= velocity of glider A after the collision.

vB´= velocity of glider B after the collision.

The momentum of the system will be:

mA · vA + mB · vB = mA · vA´ + mB · vB´

Replacing with the given data:

2.5 kg · 1.7 m/s + 2.5 kg · 0 m/s = 2.5 kg · vA´ + 2.5 kg · vB´

divide both sides of the equation by 2.5 kg:

1.7 m/s = vA´ + vB´

1.7 m/s - vA´ = vB´

Using the conservation of the kinetic energy of the system we can find vA´:

1/2 · mA · vA² + 1/2 · mB · vB² = 1/2 · mA · vA´² + 1/2 · mB · (1.7 m/s - vA´)²

Let´s replace with the given data:

1/2 · 2.5 kg · (1.7 m/s)² + 0 = 1/2 · 2.5 kg · vA´² + 1/2 · 2.5 kg · (1.7 m/s - vA´)²

divide both sides of the equation by (1/2 · 2.5 kg):

(1.7 m/s)² = vA´² + (1.7 m/s - vA´)²

(1.7 m/s)² = vA´² + (1.7 m/s)² - 2· 1.7 m/s · vA´ + vA´²

0 = 2vA´² - 2· 1.7 m/s · vA´

0 = 2vA´(vA´ - 1.7 m/s)

vA´ = 0

vA´ - 1.7 m/s = 0

vA´ = 1.7 m/s

Since the velocity of the glider A after the collision can´t be the same as before the collision, the velocity of glider A after the collision is 0 m/s.

4 0

3 years ago

A truck traveling down the highway collides with a slower moving mosquito traveling in the same direction. Which of the followin

Ipatiy [6.2K]

Answer:

B. The truck and mosquito exert the same size force on each other.

Explanation:

Newton's third law (law of action-reaction) states that

"When an object A exerts a force (action) on an object B, then object B exerts an equal and opposite force (reaction) on object A"

In this case, we can call

object A = the truck

object B = the mosquito

Thereforce according to Newton's third law, the force exerted by the truck on the mosquito is equal in magnitude to the force exerted by the mosquito on the truck (and in opposite direction).

The reason for which the mosquito will experience much more damage is the fact that the mosquito's mass is much smaller than the truck's mass, and since the acceleration is inversely proportional to the mass:

$a=\frac{F}{m}$

the mosquito will experience a much larger deceleration than the truck, therefore much more damage.

6 0

3 years ago