How much heat is needed to raise the temperature of 7g of Water by 20° C

A 2.00 kg ball is thrown upward at Some unknown angle from the top of a 20.0 M high building If the initial magnitude of the vel

mixer [17]

Answer:

792 J

Explanation:

The total energy of the ball is E = U + K where U = potential energy = mgh and K = kinetic energy = 1/2mv²

E = mgh + 1/2mv² where m = mass of ball = 2.0 kg, g = acceleration due to gravity = 9.8 m/s², h = height of building = 20.0 m, v = initial velocity of ball = 20.0 m/s.

So, substituting the values of the variables into E, we have

E = mgh + 1/2mv²

= 2.00 kg × 9.8 m/s² × 20.0 m + 1/2 × 2.00 kg × (20.0 m/s)²

= 392 J + 400 J

= 792 J

6 0

2 years ago

A bullet fired horizontally hits the ground in 0.5 sec. If it had been fired with a much higher speed in the same direction, and

stira [4]

Answer:

3. 0.5 sec.

Explanation:

A bullet fired horizontally follows a projectile motion, which consists of two independent motions:

- A horizontal motion with constant speed

- A vertical motion with constant acceleration, g = 9.8 m/s^2, towards the ground

The time taken for the bullet to reach the ground can be calculated just by considering the vertical motion:

$y(t) = h + v_{0y} t - \frac{1}{2}gt^2$

where y is the vertical position at time t, h is the initial height, and $v_{0y}$ is the initial vertical velocity of the bullet.

Since the bullet is fired horizontally, $v_{0y}=0$ . So the equation becomes

$y(t) = h - \frac{1}{2}gt^2$

And the time that the bullet takes to reach the ground can be found by requiring y=0 and solving for t:

$t=\sqrt{\frac{2h}{g}}$

As we can see, in this equation there is no dependance on the initial speed of the bullet: therefore, if the bullet is fired still horizontally but with a different speed, it will still take the same time (0.5 s) to reach the ground.

4 0

2 years ago

URGENTTT PLEASE HELP

mel-nik [20]

This doesn’t make any sense

3 0

2 years ago

A radio signal takes 1.28 s to travel from a transmitter on the Moon to the surface of Earth. The radio waves travel at 3.00108

yulyashka [42]

Answer:

s = 3.84 x 10⁸ m

Explanation:

The distance traveled by an object, while in uniform motion, is given by the following equation:

s = vt

where,

s = distance covered

v = speed

t = time interval

In this case:

s = distance between Moon and Earth = ?

v = speed of radio waves = 3 x 10⁸ m/s

t = time taken to travel = 1.28 s

Therefore,

s = (3 x 10⁸ m/s)(1.28 s)

3 0

3 years ago

1. A car drives 5 miles East and 12 miles North for 10 seconds. What is the total displacement and

telo118 [61]

Answer:

13m & 17m.

Explanation:

Displacement - Shortest distance between the initial and final point. Here ,

=> Displacement = √ ( 12² + 5² )

=> Displacement = √ 144 + 25

=> Displacement = √ 169

=> Displacement = 13 m

Distance - Total path length covered by the body .

=> Distance = 12m + 5m

=> Distance = 17m

6 0

2 years ago