PLS ANSWER FAST WILL GIVE BRAINLEST!!!!

You are on a 4 m high ladder and throw a ball upwards at 12 m/s. It lands on the ground below the ladder.

Gelneren [198K]

a) 2.75 s

The vertical position of the ball at time t is given by the equation

$y= h+ut-\frac{1}{2}gt^2$

where

h = 4 m is the initial height of the ball

u = 12 m/s is the initial velocity of the ball (upward)

g = 9.8 m/s^2 is the acceleration of gravity (downward)

We can find the time t at which the ball reaches the ground by substituting y=0 into the equation:

$0 = 4 + 12t - 4.9 t^2$

This is a second-order equation. By solving it for t, we find:

t = -0.30 s

t = 2.75 s

The first solution is negative, so we discard it; the second solution, t = 2.75 s, is the one we are looking for.

b) -15.0 m/s (downward)

The final velocity of the ball can be calculated by using the equation:

$v=u-gt$

where

u = 12 m/s is the initial (upward) velocity

g = 9.8 m/s^2 is the acceleration of gravity (downward)

t is the time

By subsisuting t = 2.75 s, we find the velocity of the ball as it reaches the ground:

$v=12 -(9.8)(2.75)=-15.0 m/s$

And the negative sign means the direction is downward.

7 0

3 years ago

The difference in outcome between the potential energy in a marshmallow burned over a campfire on the end of a stick and in one

Lapatulllka [165]

Answer:

How fast and efficient the energy is released.

Explanation:

Before burning the marshmallow energy is stored in it in the form of chemical bond energy or chemical potential energy. So upon burning this energy is released. So there will be a difference in energy release from a burned marshmallow and the one we eat straight from package.

5 0

4 years ago

A piece of aluminum foil has a known surface density of

bija089 [108]

The cube has 6 equal, square, foil faces. The mass of foil for each face is (380/6) milligrams.

The surface area of each piece is (380)/(6•11) cm^2.

The length of each side of the piece is √(380/6•11) cm

That's about 2.4 cm .

It's a cute little foil cube, just under 1-inch each way.

5 0

3 years ago

A 16.0kg canoe moving to the left at 12.5m/s makes an elastic head-on collision with a 14.0kg raft moving to the right at 16.0m/

kherson [118]

The canoe is moving at 14.1 m/s to the right after the collision.

Explanation:

According to the law of conservation of momentum, in absence of external forces the total momentum of the system must be conserved before and after the collision. So we can write:

$p_i = p_f\\m_1 u_1 + m_2 u_2 = m_1 v_1 + m_2 v_2$

where:

$m_1 = 16.0 kg$ is the mass of the canoe

$u_1 = -12.5 m/s$ is the initial velocity of canoe (we take right as positive direction, and since the canoe is moving to the left, its velocity is negative)